Commit Graph

38502 Commits

Author SHA1 Message Date
Barry Song
66ce75144d kprobes: remove duplicated strong free_insn_page in x86 and s390
free_insn_page() in x86 and s390 is same with the common weak function in
kernel/kprobes.c.  Plus, the comment "Recover page to RW mode before
releasing it" in x86 seems insensible to be there since resetting mapping
is done by common code in vfree() of module_memfree().  So drop these two
duplicated strong functions and related comment, then mark the common one
in kernel/kprobes.c strong.

Link: https://lkml.kernel.org/r/20210608065736.32656-1-song.bao.hua@hisilicon.com
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Qi Liu <liuqi115@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:06 -07:00
Andy Shevchenko
f39650de68 kernel.h: split out panic and oops helpers
kernel.h is being used as a dump for all kinds of stuff for a long time.
Here is the attempt to start cleaning it up by splitting out panic and
oops helpers.

There are several purposes of doing this:
- dropping dependency in bug.h
- dropping a loop by moving out panic_notifier.h
- unload kernel.h from something which has its own domain

At the same time convert users tree-wide to use new headers, although for
the time being include new header back to kernel.h to avoid twisted
indirected includes for existing users.

[akpm@linux-foundation.org: thread_info.h needs limits.h]
[andriy.shevchenko@linux.intel.com: ia64 fix]
  Link: https://lkml.kernel.org/r/20210520130557.55277-1-andriy.shevchenko@linux.intel.com

Link: https://lkml.kernel.org/r/20210511074137.33666-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Co-developed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Corey Minyard <cminyard@mvista.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Sebastian Reichel <sre@kernel.org>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Acked-by: Helge Deller <deller@gmx.de> # parisc
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:04 -07:00
Anshuman Khandual
1c2f7d14d8 mm/thp: define default pmd_pgtable()
Currently most platforms define pmd_pgtable() as pmd_page() duplicating
the same code all over.  Instead just define a default value i.e
pmd_page() for pmd_pgtable() and let platforms override when required via
<asm/pgtable.h>.  All the existing platform that override pmd_pgtable()
have been moved into their respective <asm/pgtable.h> header in order to
precede before the new generic definition.  This makes it much cleaner
with reduced code.

Link: https://lkml.kernel.org/r/1623646133-20306-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Stafford Horne <shorne@gmail.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:03 -07:00
Anshuman Khandual
fac7757e1f mm: define default value for FIRST_USER_ADDRESS
Currently most platforms define FIRST_USER_ADDRESS as 0UL duplication the
same code all over.  Instead just define a generic default value (i.e 0UL)
for FIRST_USER_ADDRESS and let the platforms override when required.  This
makes it much cleaner with reduced code.

The default FIRST_USER_ADDRESS here would be skipped in <linux/pgtable.h>
when the given platform overrides its value via <asm/pgtable.h>.

Link: https://lkml.kernel.org/r/1620615725-24623-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Acked-by: Guo Ren <guoren@kernel.org>			[csky]
Acked-by: Stafford Horne <shorne@gmail.com>		[openrisc]
Acked-by: Catalin Marinas <catalin.marinas@arm.com>	[arm64]
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>	[RISC-V]
Cc: Richard Henderson <rth@twiddle.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Stafford Horne <shorne@gmail.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:02 -07:00
Kefeng Wang
63703f37aa mm: generalize ZONE_[DMA|DMA32]
ZONE_[DMA|DMA32] configs have duplicate definitions on platforms that
subscribe to them.  Instead, just make them generic options which can be
selected on applicable platforms.

Also only x86/arm64 architectures could enable both ZONE_DMA and
ZONE_DMA32 if EXPERT, add ARCH_HAS_ZONE_DMA_SET to make dma zone
configurable and visible on the two architectures.

Link: https://lkml.kernel.org/r/20210528074557.17768-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>	[arm64]
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>	[RISC-V]
Acked-by: Michal Simek <michal.simek@xilinx.com>	[microblaze]
Acked-by: Michael Ellerman <mpe@ellerman.id.au>		[powerpc]
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:30 -07:00
Anshuman Khandual
cebc774fdc mm/thp: make ARCH_ENABLE_SPLIT_PMD_PTLOCK dependent on PGTABLE_LEVELS > 2
ARCH_ENABLE_SPLIT_PMD_PTLOCK is irrelevant unless there are more than two
page table levels including PMD (also per
Documentation/vm/split_page_table_lock.rst).  Make this dependency
explicit on remaining platforms i.e x86 and s390 where
ARCH_ENABLE_SPLIT_PMD_PTLOCK is subscribed.

Link: https://lkml.kernel.org/r/1622013501-20409-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> # s390
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:30 -07:00
Muchun Song
2d7a21715f mm: sparsemem: use huge PMD mapping for vmemmap pages
The preparation of splitting huge PMD mapping of vmemmap pages is ready,
so switch the mapping from PTE to PMD.

Link: https://lkml.kernel.org/r/20210616094915.34432-3-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Chen Huang <chenhuang5@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:26 -07:00
Christophe Leroy
c742199a01 mm/pgtable: add stubs for {pmd/pub}_{set/clear}_huge
For architectures with no PMD and/or no PUD, add stubs similar to what we
have for architectures without P4D.

[christophe.leroy@csgroup.eu: arm64: define only {pud/pmd}_{set/clear}_huge when useful]
  Link: https://lkml.kernel.org/r/73ec95f40cafbbb69bdfb43a7f53876fd845b0ce.1620990479.git.christophe.leroy@csgroup.eu
[christophe.leroy@csgroup.eu: x86: define only {pud/pmd}_{set/clear}_huge when useful]
  Link: https://lkml.kernel.org/r/7fbf1b6bc3e15c07c24fa45278d57064f14c896b.1620930415.git.christophe.leroy@csgroup.eu

Link: https://lkml.kernel.org/r/5ac5976419350e8e048d463a64cae449eb3ba4b0.1620795204.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:26 -07:00
Muchun Song
e9fdff87e8 mm: hugetlb: add a kernel parameter hugetlb_free_vmemmap
Add a kernel parameter hugetlb_free_vmemmap to enable the feature of
freeing unused vmemmap pages associated with each hugetlb page on boot.

We disable PMD mapping of vmemmap pages for x86-64 arch when this feature
is enabled.  Because vmemmap_remap_free() depends on vmemmap being base
page mapped.

Link: https://lkml.kernel.org/r/20210510030027.56044-8-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Barry Song <song.bao.hua@hisilicon.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Tested-by: Chen Huang <chenhuang5@huawei.com>
Tested-by: Bodeddula Balasubramaniam <bodeddub@amazon.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:25 -07:00
Muchun Song
6be24bed9d mm: hugetlb: introduce a new config HUGETLB_PAGE_FREE_VMEMMAP
The option HUGETLB_PAGE_FREE_VMEMMAP allows for the freeing of some
vmemmap pages associated with pre-allocated HugeTLB pages.  For example,
on X86_64 6 vmemmap pages of size 4KB each can be saved for each 2MB
HugeTLB page.  4094 vmemmap pages of size 4KB each can be saved for each
1GB HugeTLB page.

When a HugeTLB page is allocated or freed, the vmemmap array representing
the range associated with the page will need to be remapped.  When a page
is allocated, vmemmap pages are freed after remapping.  When a page is
freed, previously discarded vmemmap pages must be allocated before
remapping.

The config option is introduced early so that supporting code can be
written to depend on the option.  The initial version of the code only
provides support for x86-64.

If config HAVE_BOOTMEM_INFO_NODE is enabled, the freeing vmemmap page code
denpend on it to free vmemmap pages.  Otherwise, just use
free_reserved_page() to free vmemmmap pages.  The routine
register_page_bootmem_info() is used to register bootmem info.  Therefore,
make sure register_page_bootmem_info is enabled if
HUGETLB_PAGE_FREE_VMEMMAP is defined.

Link: https://lkml.kernel.org/r/20210510030027.56044-3-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Tested-by: Chen Huang <chenhuang5@huawei.com>
Tested-by: Bodeddula Balasubramaniam <bodeddub@amazon.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Barry Song <song.bao.hua@hisilicon.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:25 -07:00
Muchun Song
426e5c429d mm: memory_hotplug: factor out bootmem core functions to bootmem_info.c
Patch series "Free some vmemmap pages of HugeTLB page", v23.

This patch series will free some vmemmap pages(struct page structures)
associated with each HugeTLB page when preallocated to save memory.

In order to reduce the difficulty of the first version of code review.  In
this version, we disable PMD/huge page mapping of vmemmap if this feature
was enabled.  This acutely eliminates a bunch of the complex code doing
page table manipulation.  When this patch series is solid, we cam add the
code of vmemmap page table manipulation in the future.

The struct page structures (page structs) are used to describe a physical
page frame.  By default, there is an one-to-one mapping from a page frame
to it's corresponding page struct.

The HugeTLB pages consist of multiple base page size pages and is
supported by many architectures.  See hugetlbpage.rst in the Documentation
directory for more details.  On the x86 architecture, HugeTLB pages of
size 2MB and 1GB are currently supported.  Since the base page size on x86
is 4KB, a 2MB HugeTLB page consists of 512 base pages and a 1GB HugeTLB
page consists of 4096 base pages.  For each base page, there is a
corresponding page struct.

Within the HugeTLB subsystem, only the first 4 page structs are used to
contain unique information about a HugeTLB page.  HUGETLB_CGROUP_MIN_ORDER
provides this upper limit.  The only 'useful' information in the remaining
page structs is the compound_head field, and this field is the same for
all tail pages.

By removing redundant page structs for HugeTLB pages, memory can returned
to the buddy allocator for other uses.

When the system boot up, every 2M HugeTLB has 512 struct page structs which
size is 8 pages(sizeof(struct page) * 512 / PAGE_SIZE).

    HugeTLB                  struct pages(8 pages)         page frame(8 pages)
 +-----------+ ---virt_to_page---> +-----------+   mapping to   +-----------+
 |           |                     |     0     | -------------> |     0     |
 |           |                     +-----------+                +-----------+
 |           |                     |     1     | -------------> |     1     |
 |           |                     +-----------+                +-----------+
 |           |                     |     2     | -------------> |     2     |
 |           |                     +-----------+                +-----------+
 |           |                     |     3     | -------------> |     3     |
 |           |                     +-----------+                +-----------+
 |           |                     |     4     | -------------> |     4     |
 |    2MB    |                     +-----------+                +-----------+
 |           |                     |     5     | -------------> |     5     |
 |           |                     +-----------+                +-----------+
 |           |                     |     6     | -------------> |     6     |
 |           |                     +-----------+                +-----------+
 |           |                     |     7     | -------------> |     7     |
 |           |                     +-----------+                +-----------+
 |           |
 |           |
 |           |
 +-----------+

The value of page->compound_head is the same for all tail pages.  The
first page of page structs (page 0) associated with the HugeTLB page
contains the 4 page structs necessary to describe the HugeTLB.  The only
use of the remaining pages of page structs (page 1 to page 7) is to point
to page->compound_head.  Therefore, we can remap pages 2 to 7 to page 1.
Only 2 pages of page structs will be used for each HugeTLB page.  This
will allow us to free the remaining 6 pages to the buddy allocator.

Here is how things look after remapping.

    HugeTLB                  struct pages(8 pages)         page frame(8 pages)
 +-----------+ ---virt_to_page---> +-----------+   mapping to   +-----------+
 |           |                     |     0     | -------------> |     0     |
 |           |                     +-----------+                +-----------+
 |           |                     |     1     | -------------> |     1     |
 |           |                     +-----------+                +-----------+
 |           |                     |     2     | ----------------^ ^ ^ ^ ^ ^
 |           |                     +-----------+                   | | | | |
 |           |                     |     3     | ------------------+ | | | |
 |           |                     +-----------+                     | | | |
 |           |                     |     4     | --------------------+ | | |
 |    2MB    |                     +-----------+                       | | |
 |           |                     |     5     | ----------------------+ | |
 |           |                     +-----------+                         | |
 |           |                     |     6     | ------------------------+ |
 |           |                     +-----------+                           |
 |           |                     |     7     | --------------------------+
 |           |                     +-----------+
 |           |
 |           |
 |           |
 +-----------+

When a HugeTLB is freed to the buddy system, we should allocate 6 pages
for vmemmap pages and restore the previous mapping relationship.

Apart from 2MB HugeTLB page, we also have 1GB HugeTLB page.  It is similar
to the 2MB HugeTLB page.  We also can use this approach to free the
vmemmap pages.

In this case, for the 1GB HugeTLB page, we can save 4094 pages.  This is a
very substantial gain.  On our server, run some SPDK/QEMU applications
which will use 1024GB HugeTLB page.  With this feature enabled, we can
save ~16GB (1G hugepage)/~12GB (2MB hugepage) memory.

Because there are vmemmap page tables reconstruction on the
freeing/allocating path, it increases some overhead.  Here are some
overhead analysis.

1) Allocating 10240 2MB HugeTLB pages.

   a) With this patch series applied:
   # time echo 10240 > /proc/sys/vm/nr_hugepages

   real     0m0.166s
   user     0m0.000s
   sys      0m0.166s

   # bpftrace -e 'kprobe:alloc_fresh_huge_page { @start[tid] = nsecs; }
     kretprobe:alloc_fresh_huge_page /@start[tid]/ { @latency = hist(nsecs -
     @start[tid]); delete(@start[tid]); }'
   Attaching 2 probes...

   @latency:
   [8K, 16K)           5476 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@|
   [16K, 32K)          4760 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@       |
   [32K, 64K)             4 |                                                    |

   b) Without this patch series:
   # time echo 10240 > /proc/sys/vm/nr_hugepages

   real     0m0.067s
   user     0m0.000s
   sys      0m0.067s

   # bpftrace -e 'kprobe:alloc_fresh_huge_page { @start[tid] = nsecs; }
     kretprobe:alloc_fresh_huge_page /@start[tid]/ { @latency = hist(nsecs -
     @start[tid]); delete(@start[tid]); }'
   Attaching 2 probes...

   @latency:
   [4K, 8K)           10147 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@|
   [8K, 16K)             93 |                                                    |

   Summarize: this feature is about ~2x slower than before.

2) Freeing 10240 2MB HugeTLB pages.

   a) With this patch series applied:
   # time echo 0 > /proc/sys/vm/nr_hugepages

   real     0m0.213s
   user     0m0.000s
   sys      0m0.213s

   # bpftrace -e 'kprobe:free_pool_huge_page { @start[tid] = nsecs; }
     kretprobe:free_pool_huge_page /@start[tid]/ { @latency = hist(nsecs -
     @start[tid]); delete(@start[tid]); }'
   Attaching 2 probes...

   @latency:
   [8K, 16K)              6 |                                                    |
   [16K, 32K)         10227 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@|
   [32K, 64K)             7 |                                                    |

   b) Without this patch series:
   # time echo 0 > /proc/sys/vm/nr_hugepages

   real     0m0.081s
   user     0m0.000s
   sys      0m0.081s

   # bpftrace -e 'kprobe:free_pool_huge_page { @start[tid] = nsecs; }
     kretprobe:free_pool_huge_page /@start[tid]/ { @latency = hist(nsecs -
     @start[tid]); delete(@start[tid]); }'
   Attaching 2 probes...

   @latency:
   [4K, 8K)            6805 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@|
   [8K, 16K)           3427 |@@@@@@@@@@@@@@@@@@@@@@@@@@                          |
   [16K, 32K)             8 |                                                    |

   Summary: The overhead of __free_hugepage is about ~2-3x slower than before.

Although the overhead has increased, the overhead is not significant.
Like Mike said, "However, remember that the majority of use cases create
HugeTLB pages at or shortly after boot time and add them to the pool.  So,
additional overhead is at pool creation time.  There is no change to
'normal run time' operations of getting a page from or returning a page to
the pool (think page fault/unmap)".

Despite the overhead and in addition to the memory gains from this series.
The following data is obtained by Joao Martins.  Very thanks to his
effort.

There's an additional benefit which is page (un)pinners will see an improvement
and Joao presumes because there are fewer memmap pages and thus the tail/head
pages are staying in cache more often.

Out of the box Joao saw (when comparing linux-next against linux-next +
this series) with gup_test and pinning a 16G HugeTLB file (with 1G pages):

	get_user_pages(): ~32k -> ~9k
	unpin_user_pages(): ~75k -> ~70k

Usually any tight loop fetching compound_head(), or reading tail pages
data (e.g.  compound_head) benefit a lot.  There's some unpinning
inefficiencies Joao was fixing[2], but with that in added it shows even
more:

	unpin_user_pages(): ~27k -> ~3.8k

[1] https://lore.kernel.org/linux-mm/20210409205254.242291-1-mike.kravetz@oracle.com/
[2] https://lore.kernel.org/linux-mm/20210204202500.26474-1-joao.m.martins@oracle.com/

This patch (of 9):

Move bootmem info registration common API to individual bootmem_info.c.
And we will use {get,put}_page_bootmem() to initialize the page for the
vmemmap pages or free the vmemmap pages to buddy in the later patch.  So
move them out of CONFIG_MEMORY_HOTPLUG_SPARSE.  This is just code movement
without any functional change.

Link: https://lkml.kernel.org/r/20210510030027.56044-1-songmuchun@bytedance.com
Link: https://lkml.kernel.org/r/20210510030027.56044-2-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Tested-by: Chen Huang <chenhuang5@huawei.com>
Tested-by: Bodeddula Balasubramaniam <bodeddub@amazon.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Mina Almasry <almasrymina@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Barry Song <song.bao.hua@hisilicon.com>
Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:25 -07:00
Naoya Horiguchi
a3f5d80ea4 mm,hwpoison: send SIGBUS with error virutal address
Now an action required MCE in already hwpoisoned address surely sends a
SIGBUS to current process, but the SIGBUS doesn't convey error virtual
address.  That's not optimal for hwpoison-aware applications.

To fix the issue, make memory_failure() call kill_accessing_process(),
that does pagetable walk to find the error virtual address.  It could find
multiple virtual addresses for the same error page, and it seems hard to
tell which virtual address is correct one.  But that's rare and sending
incorrect virtual address could be better than no address.  So let's
report the first found virtual address for now.

[naoya.horiguchi@nec.com: fix walk_page_range() return]
  Link: https://lkml.kernel.org/r/20210603051055.GA244241@hori.linux.bs1.fc.nec.co.jp

Link: https://lkml.kernel.org/r/20210521030156.2612074-4-nao.horiguchi@gmail.com
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Aili Yao <yaoaili@kingsoft.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Jue Wang <juew@google.com>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:55 -07:00
Mike Rapoport
a9ee6cf5c6 mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA
After removal of DISCINTIGMEM the NEED_MULTIPLE_NODES and NUMA
configuration options are equivalent.

Drop CONFIG_NEED_MULTIPLE_NODES and use CONFIG_NUMA instead.

Done with

	$ sed -i 's/CONFIG_NEED_MULTIPLE_NODES/CONFIG_NUMA/' \
		$(git grep -wl CONFIG_NEED_MULTIPLE_NODES)
	$ sed -i 's/NEED_MULTIPLE_NODES/NUMA/' \
		$(git grep -wl NEED_MULTIPLE_NODES)

with manual tweaks afterwards.

[rppt@linux.ibm.com: fix arm boot crash]
  Link: https://lkml.kernel.org/r/YMj9vHhHOiCVN4BF@linux.ibm.com

Link: https://lkml.kernel.org/r/20210608091316.3622-9-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:55 -07:00
Liam Howlett
9ce2c3fc0b x86/sgx: use vma_lookup() in sgx_encl_find()
Use vma_lookup() to find the VMA at a specific address.  As vma_lookup()
will return NULL if the address is not within any VMA, the start address
no longer needs to be validated.

Link: https://lkml.kernel.org/r/20210521174745.2219620-10-Liam.Howlett@Oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:51 -07:00
David Hildenbrand
a4eec6a3df binfmt: remove in-tree usage of MAP_EXECUTABLE
Ever since commit e9714acf8c ("mm: kill vma flag VM_EXECUTABLE and
mm->num_exe_file_vmas"), VM_EXECUTABLE is gone and MAP_EXECUTABLE is
essentially completely ignored.  Let's remove all usage of MAP_EXECUTABLE.

[akpm@linux-foundation.org: fix blooper in fs/binfmt_aout.c. per David]

Link: https://lkml.kernel.org/r/20210421093453.6904-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kevin Brodsky <Kevin.Brodsky@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:50 -07:00
Linus Torvalds
94ca94bbbb Two more urgent FPU fixes:
- prevent unprivileged userspace from reinitializing supervisor states
 
  - Prepare init_fpstate, which is the buffer used when initializing
  FPU state, properly in case the skip-writing-state-components XSAVE*
  variants are used.
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmDVltYACgkQEsHwGGHe
 VUqY9Q//c4MhJP2E15cqTWupxYk41k0UMjqPIwGmt6hRoDNKeFQm0xSgeOwe2mgk
 bbzGDJOfAi2Hxza2fw6No4wIiaB3sZIqK451aI1SM9HTDB/B/dMGBPXAp9qRlnbT
 kU/rDqQVqi7wlwunSunFoSLTwmQw0Lispmzwz9yirdQ+jVsnuTLWtPbUZM8RL/j8
 XAhVwhDNc+Wuw0OBvRsyP5Mp6k9+2ic6z2ObIgSfgp4GeDG2F/+ZQ5W5ZeHVGQda
 5QqKIdWCmAinzdz3N0iksthT3RJwLmYZ0K/qvLMrYNCvZiuUBdgrUn1Yrjo1c3lx
 W+SUMtgehlylfyBbyGn5zBbJtZJtflx+kYLHLzw58lWC+ekRfxqx2F+e7S4facXr
 Xn9IpnIAhru1/SAItSvScxXzjVW4DwZKO3tLr+/KsrRsTnS15pD6rx6OK88HHP/y
 ofjCeS0P8STb7/Gzzqj7c+7bJvSZo/h7jmF+H2y5tRhUXZogSoh1z/QGYpvcFrwP
 GOZeACREBv+D1PQNp/DN/ZiZHg6+csEg+3abtRaZSbdnfsCSpU/imXcX9GPco5vu
 XS+Gxle2aqvRmQNuJEbNr7YDfocZWWXmXnkPSKCtvqSgNdxjFjZ2v3TRTAgvHEoS
 Otpsv5Hk9g0FCep4oHG3zv8cb+Nk7Ycl2ZLZXQwE2Egane6U4K8=
 =uqQE
 -----END PGP SIGNATURE-----

Merge tag 'x86_urgent_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Borislav Petkov:
 "Two more urgent FPU fixes:

   - prevent unprivileged userspace from reinitializing supervisor
     states

   - prepare init_fpstate, which is the buffer used when initializing
     FPU state, properly in case the skip-writing-state-components
     XSAVE* variants are used"

* tag 'x86_urgent_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu: Make init_fpstate correct with optimized XSAVE
  x86/fpu: Preserve supervisor states in sanitize_restored_user_xstate()
2021-06-25 10:00:25 -07:00
Linus Torvalds
df50110004 An LBR buffer fix for code that probably only worked accidentally.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmDULYwRHG1pbmdvQGtl
 cm5lbC5vcmcACgkQEnMQ0APhK1gLZRAAhGPpPwb59c38IfGkXivuSf4bCmNeJzru
 YuyNsbvhc4bYPXAvOEdpaa6fVGEzwYD5MEaU3JjNfTnX9sREJVN2fwipAA8h5enL
 zAOm1ZTZ/0J9mSUpJpL+1kq3Ae7BHc/yJo/wvHlVuzz/HAp1y1O5FWo4An10vOf3
 qiKDvj0e7VGXTWh0S8z0+iv7SuMa3+I/9yqcQ5DaxJKZTlQPuK4H6Fge8KDenO0z
 fj0IfEemXb75lQkq/eaQ5Fj5UFLqRFWTihuVRyH93V7dKAIq8aybdyaqQPp8NtdT
 YdMYPNeCG8uRNwtIoDQHsVpfkkhF1y/Y8Klg0LpNQCAdrcKy0wvkaVMWCcP7ELsD
 Nyi/wJEaM3vLYHjxGpk1HTYEC50Vi4Dz6+tFD9LubVW7PCAMasZqkKkvvslO/Xtc
 ZjPIju4u7bIzxTUBpBbxuPKJXUPt70OR6SZtGxMXDosOqI8a8yOuAaO+FEX51kp/
 MxcJPSBfZlt+GPpa6LzA6Uskev1HW2+wLxhM87b6Eqt7pYFGVy7UErvmxV5q6nTu
 tUaL+5Zt7/DKWwtXHKRMgZBYQbKYt1Y9s1JKYEeMEwlIP95x7x1cY/p+pw5pwlIm
 uVT8evJAdLR+3faqhGlNtYdczZXaI/CwyHDnvIuSdScdc/bZ9zjEw/vQFVaYP1Db
 uhyQpjR3qlI=
 =HVxR
 -----END PGP SIGNATURE-----

Merge tag 'perf-urgent-2021-06-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 perf fix from Ingo Molnar:
 "An LBR buffer fix for code that probably only worked accidentally"

* tag 'perf-urgent-2021-06-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel/lbr: Zero the xstate buffer on allocation
2021-06-24 08:55:12 -07:00
Thomas Gleixner
7f049fbdd5 perf/x86/intel/lbr: Zero the xstate buffer on allocation
XRSTORS requires a valid xstate buffer to work correctly. XSAVES does not
guarantee to write a fully valid buffer according to the SDM:

  "XSAVES does not write to any parts of the XSAVE header other than the
   XSTATE_BV and XCOMP_BV fields."

XRSTORS triggers a #GP:

  "If bytes 63:16 of the XSAVE header are not all zero."

It's dubious at best how this can work at all when the buffer is not zeroed
before use.

Allocate the buffers with __GFP_ZERO to prevent XRSTORS failure.

Fixes: ce711ea3ca ("perf/x86/intel/lbr: Support XSAVES/XRSTORS for LBR context switch")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/87wnr0wo2z.ffs@nanos.tec.linutronix.de
2021-06-24 08:49:03 +02:00
Peter Zijlstra
1f008d46f1 x86: Always inline task_size_max()
Fix:

  vmlinux.o: warning: objtool: handle_bug()+0x10: call to task_size_max() leaves .noinstr.text section

When #UD isn't a BUG, we shouldn't violate noinstr (we'll still
probably die, but that's another story).

Fixes: 025768a966 ("x86/cpu: Use alternative to generate the TASK_SIZE_MAX constant")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210621120120.682468274@infradead.org
2021-06-22 13:56:43 +02:00
Peter Zijlstra
4c9c26f1e6 x86/xen: Fix noinstr fail in exc_xen_unknown_trap()
Fix:

  vmlinux.o: warning: objtool: exc_xen_unknown_trap()+0x7: call to printk() leaves .noinstr.text section

Fixes: 2e92493637 ("x86/xen: avoid warning in Xen pv guest with CONFIG_AMD_MEM_ENCRYPT enabled")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210621120120.606560778@infradead.org
2021-06-22 13:56:42 +02:00
Peter Zijlstra
84e60065df x86/xen: Fix noinstr fail in xen_pv_evtchn_do_upcall()
Fix:

  vmlinux.o: warning: objtool: xen_pv_evtchn_do_upcall()+0x23: call to irq_enter_rcu() leaves .noinstr.text section

Fixes: 359f01d181 ("x86/entry: Use run_sysvec_on_irqstack_cond() for XEN upcall")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210621120120.532960208@infradead.org
2021-06-22 13:56:42 +02:00
Peter Zijlstra
240001d4e3 x86/entry: Fix noinstr fail in __do_fast_syscall_32()
Fix:

  vmlinux.o: warning: objtool: __do_fast_syscall_32()+0xf5: call to trace_hardirqs_off() leaves .noinstr.text section

Fixes: 5d5675df79 ("x86/entry: Fix entry/exit mismatch on failed fast 32-bit syscalls")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210621120120.467898710@infradead.org
2021-06-22 13:56:42 +02:00
Thomas Gleixner
f9dfb5e390 x86/fpu: Make init_fpstate correct with optimized XSAVE
The XSAVE init code initializes all enabled and supported components with
XRSTOR(S) to init state. Then it XSAVEs the state of the components back
into init_fpstate which is used in several places to fill in the init state
of components.

This works correctly with XSAVE, but not with XSAVEOPT and XSAVES because
those use the init optimization and skip writing state of components which
are in init state. So init_fpstate.xsave still contains all zeroes after
this operation.

There are two ways to solve that:

   1) Use XSAVE unconditionally, but that requires to reshuffle the buffer when
      XSAVES is enabled because XSAVES uses compacted format.

   2) Save the components which are known to have a non-zero init state by other
      means.

Looking deeper, #2 is the right thing to do because all components the
kernel supports have all-zeroes init state except the legacy features (FP,
SSE). Those cannot be hard coded because the states are not identical on all
CPUs, but they can be saved with FXSAVE which avoids all conditionals.

Use FXSAVE to save the legacy FP/SSE components in init_fpstate along with
a BUILD_BUG_ON() which reminds developers to validate that a newly added
component has all zeroes init state. As a bonus remove the now unused
copy_xregs_to_kernel_booting() crutch.

The XSAVE and reshuffle method can still be implemented in the unlikely
case that components are added which have a non-zero init state and no
other means to save them. For now, FXSAVE is just simple and good enough.

  [ bp: Fix a typo or two in the text. ]

Fixes: 6bad06b768 ("x86, xsave: Use xsaveopt in context-switch path when supported")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20210618143444.587311343@linutronix.de
2021-06-22 11:06:21 +02:00
Thomas Gleixner
9301982c42 x86/fpu: Preserve supervisor states in sanitize_restored_user_xstate()
sanitize_restored_user_xstate() preserves the supervisor states only
when the fx_only argument is zero, which allows unprivileged user space
to put supervisor states back into init state.

Preserve them unconditionally.

 [ bp: Fix a typo or two in the text. ]

Fixes: 5d6b6a6f9b ("x86/fpu/xstate: Update sanitize_restored_xstate() for supervisor xstates")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20210618143444.438635017@linutronix.de
2021-06-22 10:51:23 +02:00
Peter Zijlstra
31197d3a0f objtool/x86: Ignore __x86_indirect_alt_* symbols
Because the __x86_indirect_alt* symbols are just that, objtool will
try and validate them as regular symbols, instead of the alternative
replacements that they are.

This goes sideways for FRAME_POINTER=y builds; which generate a fair
amount of warnings.

Fixes: 9bc0bb5072 ("objtool/x86: Rewrite retpoline thunk calls")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/YNCgxwLBiK9wclYJ@hirez.programming.kicks-ass.net
2021-06-21 17:26:57 +02:00
Linus Torvalds
8363e795eb A first set of urgent fixes to the FPU/XSTATE handling mess^W code.
(There's a lot more in the pipe):
 
 - Prevent corruption of the XSTATE buffer in signal handling by
   validating what is being copied from userspace first.
 
 - Invalidate other task's preserved FPU registers on XRSTOR failure
   (#PF) because latter can still modify some of them.
 
 - Restore the proper PKRU value in case userspace modified it
 
 - Reset FPU state when signal restoring fails
 
 Other:
 
 - Map EFI boot services data memory as encrypted in a SEV guest so that
   the guest can access it and actually boot properly
 
 - Two SGX correctness fixes: proper resources freeing and a NUMA fix
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmDO5vQACgkQEsHwGGHe
 VUrUjw//fRU8BPZ3/SWNQO188QhHdFpm3jqtjRJsZD1FfnnLdxIg2SCP4RjFxv+Y
 eFyN0nYLekG8a3CMV081H9Rhr5tt3bflk0oTcGAar7m2qQiCiqaAH0wptIlQonSu
 nQCSs+PeaaK4nRCtW+TUJnwG0ZU/y7fEXa3pxJ6hSMnxZjz3lj70zKhpA1nQtqRZ
 OOStvBNtaWcDdTTE4r8XuFIxuMUUEuwHlQQmkAVHQYUf6vxGYfnDYEg83Wddvq1E
 1leSRNFlLcCAbPUV/fax3KGvaekeJ1U411uWqXlain6m105+mk+irmrLxtur/lJ5
 cWTVb5CbIHFZnJvC5jzNPv/03GbIIQaVm4jPI2qB1AZbjcVlAPKj1Ne+U1fzvmDT
 wNUob/rnIXiGptvtUMNYGURxBTj65Nnom3iAJV+AdMOThDwYMvsJJjFkMnC5wO2n
 ZAexumWPnUzWoxSMTraT7a6b/kilFUrcPljxSrFd9yVeU8E6a1OSW35oWoQ3itrc
 xx/ne8RodLmCPC9DjecFcQR+qUuXsF+XCCj07QpfKNTAObr17e9nsKJneR6MX79C
 Lpc7Ka/CiTGYcebWX7tqtjwGPfa6iqekswxYRRp7j54bQ4sHmKyordZy0Q8+c079
 gmMlPdNbqQg3YwHyXW2yeJETDS1HBp61RRojAP15BsL73wyYQNE=
 =AuXr
 -----END PGP SIGNATURE-----

Merge tag 'x86_urgent_for_v5.13_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Borislav Petkov:
 "A first set of urgent fixes to the FPU/XSTATE handling mess^W code.
  (There's a lot more in the pipe):

   - Prevent corruption of the XSTATE buffer in signal handling by
     validating what is being copied from userspace first.

   - Invalidate other task's preserved FPU registers on XRSTOR failure
     (#PF) because latter can still modify some of them.

   - Restore the proper PKRU value in case userspace modified it

   - Reset FPU state when signal restoring fails

  Other:

   - Map EFI boot services data memory as encrypted in a SEV guest so
     that the guest can access it and actually boot properly

   - Two SGX correctness fixes: proper resources freeing and a NUMA fix"

* tag 'x86_urgent_for_v5.13_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Avoid truncating memblocks for SGX memory
  x86/sgx: Add missing xa_destroy() when virtual EPC is destroyed
  x86/fpu: Reset state for all signal restore failures
  x86/pkru: Write hardware init value to PKRU when xstate is init
  x86/process: Check PF_KTHREAD and not current->mm for kernel threads
  x86/fpu: Invalidate FPU state after a failed XRSTOR from a user buffer
  x86/fpu: Prevent state corruption in __fpu__restore_sig()
  x86/ioremap: Map EFI-reserved memory as encrypted for SEV
2021-06-20 09:09:58 -07:00
Linus Torvalds
728a748b3f pci-v5.13-fixes-2
-----BEGIN PGP SIGNATURE-----
 
 iQJIBAABCgAyFiEEgMe7l+5h9hnxdsnuWYigwDrT+vwFAmDM/J8UHGJoZWxnYWFz
 QGdvb2dsZS5jb20ACgkQWYigwDrT+vzAWBAAgHd/Taycg2JT1QakC2qkUPfipB2w
 IQWAzRAODWEXBOsgdck4H5q7y4dzxHdj4BmZIe0iPmc0LkqrqjYiKvYZzqdLzRlG
 4SC12h7DLOBfPluKDfjB3Ceo0TlpAWM9c6Gm2liMscLJMMw8JcrnZK+pP03ws66O
 3UjHRF+tJTDUqGUeOn45MVlkVSk5wIOG+hgGbI3AEGPvegteK0J97xJ8GI4MUi58
 Uy5VMFB+ETOxvbzWAAiRIko4YkSjVNb1pme21Izi6z2FMldmUb9nECp6zSJzxj5t
 H6/8ehgzHDIoyak0DDzyS2rOL4D1jIqymEKQIIK2frODaRYSSYUR/vtXkhO/bxPf
 aJ9uFJQFZei98cSiONmq1NDJAMEMa21b32MfK5sOizJJ7ANljBFz+eVY0L+Mr+wy
 WQf8EiBXBCS2v3CQzS7iA+l8R6rvvf+VjDkqpe/ca1GrAeZ1UzdmU2vf9hcEW+Iu
 MJ1b6AtTTMAQIdZyTVFz+k/FR3jJyZBGavZFi8+I0Tgui0dooiCwmSgxJptVQrjr
 DydIiJ2Zgtq22T388aVeDL5X4xDcqWlHoamfHuBedxS/ti75Es7sexitkhMW+Sda
 Ygqb5Cvfyg8GdKvgvDZz59wg/+LNhhwt81ZoxD/RvDXmURyANA3l9GnTxBgq9BZb
 wCGLm4ZWP/AFe9g=
 =CY2S
 -----END PGP SIGNATURE-----

Merge tag 'pci-v5.13-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull PCI fixes from Bjorn Helgaas:

 - Clear 64-bit flag for host bridge windows below 4GB to fix a resource
   allocation regression added in -rc1 (Punit Agrawal)

 - Fix tegra194 MCFG quirk build regressions added in -rc1 (Jon Hunter)

 - Avoid secondary bus resets on TI KeyStone C667X devices (Antti
   Järvinen)

 - Avoid secondary bus resets on some NVIDIA GPUs (Shanker Donthineni)

 - Work around FLR erratum on Huawei Intelligent NIC VF (Chiqijun)

 - Avoid broken ATS on AMD Navi14 GPU (Evan Quan)

 - Trust Broadcom BCM57414 NIC to isolate functions even though it
   doesn't advertise ACS support (Sriharsha Basavapatna)

 - Work around AMD RS690 BIOSes that don't configure DMA above 4GB
   (Mikel Rychliski)

 - Fix panic during PIO transfer on Aardvark controller (Pali Rohár)

* tag 'pci-v5.13-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: aardvark: Fix kernel panic during PIO transfer
  PCI: Add AMD RS690 quirk to enable 64-bit DMA
  PCI: Add ACS quirk for Broadcom BCM57414 NIC
  PCI: Mark AMD Navi14 GPU ATS as broken
  PCI: Work around Huawei Intelligent NIC VF FLR erratum
  PCI: Mark some NVIDIA GPUs to avoid bus reset
  PCI: Mark TI C667X to avoid bus reset
  PCI: tegra194: Fix MCFG quirk build regressions
  PCI: of: Clear 64-bit flag for non-prefetchable memory below 4GB
2021-06-18 13:54:11 -07:00
Fan Du
28e5e44aa3 x86/mm: Avoid truncating memblocks for SGX memory
tl;dr:

Several SGX users reported seeing the following message on NUMA systems:

  sgx: [Firmware Bug]: Unable to map EPC section to online node. Fallback to the NUMA node 0.

This turned out to be the memblock code mistakenly throwing away SGX
memory.

=== Full Changelog ===

The 'max_pfn' variable represents the highest known RAM address.  It can
be used, for instance, to quickly determine for which physical addresses
there is mem_map[] space allocated.  The numa_meminfo code makes an
effort to throw out ("trim") all memory blocks which are above 'max_pfn'.

SGX memory is not considered RAM (it is marked as "Reserved" in the
e820) and is not taken into account by max_pfn. Despite this, SGX memory
areas have NUMA affinity and are enumerated in the ACPI SRAT table. The
existing SGX code uses the numa_meminfo mechanism to look up the NUMA
affinity for its memory areas.

In cases where SGX memory was above max_pfn (usually just the one EPC
section in the last highest NUMA node), the numa_memblock is truncated
at 'max_pfn', which is below the SGX memory.  When the SGX code tries to
look up the affinity of this memory, it fails and produces an error message:

  sgx: [Firmware Bug]: Unable to map EPC section to online node. Fallback to the NUMA node 0.

and assigns the memory to NUMA node 0.

Instead of silently truncating the memory block at 'max_pfn' and
dropping the SGX memory, add the truncated portion to
'numa_reserved_meminfo'.  This allows the SGX code to later determine
the NUMA affinity of its 'Reserved' area.

Before, numa_meminfo looked like this (from 'crash'):

  blk = { start =          0x0, end = 0x2080000000, nid = 0x0 }
        { start = 0x2080000000, end = 0x4000000000, nid = 0x1 }

numa_reserved_meminfo is empty.

With this, numa_meminfo looks like this:

  blk = { start =          0x0, end = 0x2080000000, nid = 0x0 }
        { start = 0x2080000000, end = 0x4000000000, nid = 0x1 }

and numa_reserved_meminfo has an entry for node 1's SGX memory:

  blk =  { start = 0x4000000000, end = 0x4080000000, nid = 0x1 }

 [ daveh: completely rewrote/reworked changelog ]

Fixes: 5d30f92e76 ("x86/NUMA: Provide a range-to-target_node lookup facility")
Reported-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fan Du <fan.du@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20210617194657.0A99CB22@viggo.jf.intel.com
2021-06-18 19:37:01 +02:00
Mikel Rychliski
cacf994a91 PCI: Add AMD RS690 quirk to enable 64-bit DMA
Although the AMD RS690 chipset has 64-bit DMA support, BIOS implementations
sometimes fail to configure the memory limit registers correctly.

The Acer F690GVM mainboard uses this chipset and a Marvell 88E8056 NIC. The
sky2 driver programs the NIC to use 64-bit DMA, which will not work:

  sky2 0000:02:00.0: error interrupt status=0x8
  sky2 0000:02:00.0 eth0: tx timeout
  sky2 0000:02:00.0 eth0: transmit ring 0 .. 22 report=0 done=0

Other drivers required by this mainboard either don't support 64-bit DMA,
or have it disabled using driver specific quirks. For example, the ahci
driver has quirks to enable or disable 64-bit DMA depending on the BIOS
version (see ahci_sb600_enable_64bit() in ahci.c). This ahci quirk matches
against the SB600 SATA controller, but the real issue is almost certainly
with the RS690 PCI host that it was commonly attached to.

To avoid this issue in all drivers with 64-bit DMA support, fix the
configuration of the PCI host. If the kernel is aware of physical memory
above 4GB, but the BIOS never configured the PCI host with this
information, update the registers with our values.

[bhelgaas: drop PCI_DEVICE_ID_ATI_RS690 definition]
Link: https://lore.kernel.org/r/20210611214823.4898-1-mikel@mikelr.com
Signed-off-by: Mikel Rychliski <mikel@mikelr.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2021-06-18 10:32:35 -05:00
Linus Torvalds
fd0aa1a456 Miscellaneous bugfixes. The main interesting one is a NULL pointer dereference
reported by syzkaller ("KVM: x86: Immediately reset the MMU context when the SMM
 flag is cleared").
 -----BEGIN PGP SIGNATURE-----
 
 iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAmDLldwUHHBib256aW5p
 QHJlZGhhdC5jb20ACgkQv/vSX3jHroPTOgf/XpAehLdWlx2877ulcBD0Kjt0tLvH
 OFHRD1Ir0d1Ay3DX8qmxLquXHB4CoDGZBwi1d7AI165kUP/XLmV0bY6TZ74inI/P
 CaD8Bsbm8+iBl5jrovEPc+223bK+3OFOvo2pk6M/MlsO/ExRikaPDtHOnkfousbl
 nLX8v2qd7ihWyJOdLJMU9pV8E2iczQoCuH9yWBHdCrxRxWtPzkEekPWb0sujByiF
 4tD7sqiEA3ugbF1Wm5keQV63NLplfxx+Zun0FV+tbpjjxQWAGl81dP+zmqok0sM/
 qQCyZevt6jLLkL+Fn6hI6PP9OTeYreX2fgwhWXs71d2js33yNg5Veqx5Bw==
 =Gs/y
 -----END PGP SIGNATURE-----

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:
 "Miscellaneous bugfixes.

  The main interesting one is a NULL pointer dereference reported by
  syzkaller ("KVM: x86: Immediately reset the MMU context when the SMM
  flag is cleared")"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: selftests: Fix kvm_check_cap() assertion
  KVM: x86/mmu: Calculate and check "full" mmu_role for nested MMU
  KVM: X86: Fix x86_emulator slab cache leak
  KVM: SVM: Call SEV Guest Decommission if ASID binding fails
  KVM: x86: Immediately reset the MMU context when the SMM flag is cleared
  KVM: x86: Fix fall-through warnings for Clang
  KVM: SVM: fix doc warnings
  KVM: selftests: Fix compiling errors when initializing the static structure
  kvm: LAPIC: Restore guard to prevent illegal APIC register access
2021-06-17 13:14:53 -07:00
Kai Huang
4692bc775d x86/sgx: Add missing xa_destroy() when virtual EPC is destroyed
xa_destroy() needs to be called to destroy a virtual EPC's page array
before calling kfree() to free the virtual EPC. Currently it is not
called so add the missing xa_destroy().

Fixes: 540745ddbc ("x86/sgx: Introduce virtual EPC for use by KVM guests")
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Tested-by: Yang Zhong <yang.zhong@intel.com>
Link: https://lkml.kernel.org/r/20210615101639.291929-1-kai.huang@intel.com
2021-06-15 18:03:45 +02:00
Linus Torvalds
191aaf6cc4 Misc fixes:
- Fix the NMI watchdog on ancient Intel CPUs
 
  - Remove a misguided, NMI-unsafe KASAN callback
    from the NMI-safe irq_work path used by perf.
 
  - Fix uncore events on Ice Lake servers.
 
  - Someone booted maxcpus=1 on an SNB-EP, and the
    uncore driver emitted warnings and was probably
    buggy. Fix it.
 
  - KCSAN found a genuine data race in the core perf
    code. Somewhat ironically the bug was introduced
    through a recent race fix. :-/ In our defense, the
    new race window was much more narrow. Fix it.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmDErJkRHG1pbmdvQGtl
 cm5lbC5vcmcACgkQEnMQ0APhK1gjNxAAhWPl+zsVr+bMZGQVnjPf7swXSaqsphtU
 LrP0hrs4nH0JiB7lZJVjPhCMQKXb+gvP0CTmxkOXmNORDKDK3slIS/zp9uyH1F+d
 nXhmWi7c1bHU0vortnv87LGJpeeI1E7rQ/uBxK6b2v6kOBmCnjvQEiPvJEIGTtpE
 YimVBERdPDTBQiW5EQbbyL3VScwm5QUN2STnLPjUtVc9HES/zCdhXNlsASfhn/Tn
 8rlSAqVEOUcsTpTXYadHckNi1zn4zrpuhWKpSHXrvXCo3qU8QpISjYNwAJ/0IGBj
 CMdg2r+MneF6gop76R5aRcA0JDvDgtv56LKFVhi9gEkE5em9YAni17HU0IeTvJmT
 mL9j64h8oUErC/TpAU1vXCJjIxH7jLq8YQoNwHUvF0pSvcNGsaFeWu1ADQuTEIi9
 fyKHRpFwPMBhwc+AMaRepgQ9FlvE4567fQmwlrUDUKlCU0x0dfvFCM2z/o61YFlH
 oFgB0h0SNxdoj5EXny50LtokP1Kp/oBNVhhNsUpH8wVxWLi61BHJOslcc7nzdP6t
 JBqVE6bLQlxmlKt2AwiOkxe9xVv34o3AMxUYtUBYgCTZSlRjL//7pcqgG5r+CZH/
 eXEU3wWcGtRPEItGXtiGT9Vm2ZYSaUMFF7k7OrTPCHgkW51oEW4FUoaV7M+9fl43
 638x9Wnse4Q=
 =9LoT
 -----END PGP SIGNATURE-----

Merge tag 'perf-urgent-2021-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fixes from Ingo Molnar:
 "Misc fixes:

   - Fix the NMI watchdog on ancient Intel CPUs

   - Remove a misguided, NMI-unsafe KASAN callback from the NMI-safe
     irq_work path used by perf.

   - Fix uncore events on Ice Lake servers.

   - Someone booted maxcpus=1 on an SNB-EP, and the uncore driver
     emitted warnings and was probably buggy. Fix it.

   - KCSAN found a genuine data race in the core perf code. Somewhat
     ironically the bug was introduced through a recent race fix. :-/
     In our defense, the new race window was much more narrow. Fix it"

* tag 'perf-urgent-2021-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/nmi_watchdog: Fix old-style NMI watchdog regression on old Intel CPUs
  irq_work: Make irq_work_queue() NMI-safe again
  perf/x86/intel/uncore: Fix M2M event umask for Ice Lake server
  perf/x86/intel/uncore: Fix a kernel WARNING triggered by maxcpus=1
  perf: Fix data race between pin_count increment/decrement
2021-06-12 11:34:49 -07:00
Tor Vic
2398ce8015 x86, lto: Pass -stack-alignment only on LLD < 13.0.0
Since LLVM commit 3787ee4, the '-stack-alignment' flag has been dropped
[1], leading to the following error message when building a LTO kernel
with Clang-13 and LLD-13:

    ld.lld: error: -plugin-opt=-: ld.lld: Unknown command line argument
    '-stack-alignment=8'.  Try 'ld.lld --help'
    ld.lld: Did you mean '--stackrealign=8'?

It also appears that the '-code-model' flag is not necessary anymore
starting with LLVM-9 [2].

Drop '-code-model' and make '-stack-alignment' conditional on LLD < 13.0.0.

These flags were necessary because these flags were not encoded in the
IR properly, so the link would restart optimizations without them. Now
there are properly encoded in the IR, and these flags exposing
implementation details are no longer necessary.

[1] https://reviews.llvm.org/D103048
[2] https://reviews.llvm.org/D52322

Cc: stable@vger.kernel.org
Link: https://github.com/ClangBuiltLinux/linux/issues/1377
Signed-off-by: Tor Vic <torvic9@mailbox.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/f2c018ee-5999-741e-58d4-e482d5246067@mailbox.org
2021-06-11 10:33:45 -07:00
Sean Christopherson
654430efde KVM: x86/mmu: Calculate and check "full" mmu_role for nested MMU
Calculate and check the full mmu_role when initializing the MMU context
for the nested MMU, where "full" means the bits and pieces of the role
that aren't handled by kvm_calc_mmu_role_common().  While the nested MMU
isn't used for shadow paging, things like the number of levels in the
guest's page tables are surprisingly important when walking the guest
page tables.  Failure to reinitialize the nested MMU context if L2's
paging mode changes can result in unexpected and/or missed page faults,
and likely other explosions.

E.g. if an L1 vCPU is running both a 32-bit PAE L2 and a 64-bit L2, the
"common" role calculation will yield the same role for both L2s.  If the
64-bit L2 is run after the 32-bit PAE L2, L0 will fail to reinitialize
the nested MMU context, ultimately resulting in a bad walk of L2's page
tables as the MMU will still have a guest root_level of PT32E_ROOT_LEVEL.

  WARNING: CPU: 4 PID: 167334 at arch/x86/kvm/vmx/vmx.c:3075 ept_save_pdptrs+0x15/0xe0 [kvm_intel]
  Modules linked in: kvm_intel]
  CPU: 4 PID: 167334 Comm: CPU 3/KVM Not tainted 5.13.0-rc1-d849817d5673-reqs #185
  Hardware name: ASUS Q87M-E/Q87M-E, BIOS 1102 03/03/2014
  RIP: 0010:ept_save_pdptrs+0x15/0xe0 [kvm_intel]
  Code: <0f> 0b c3 f6 87 d8 02 00f
  RSP: 0018:ffffbba702dbba00 EFLAGS: 00010202
  RAX: 0000000000000011 RBX: 0000000000000002 RCX: ffffffff810a2c08
  RDX: ffff91d7bc30acc0 RSI: 0000000000000011 RDI: ffff91d7bc30a600
  RBP: ffff91d7bc30a600 R08: 0000000000000010 R09: 0000000000000007
  R10: 0000000000000000 R11: 0000000000000000 R12: ffff91d7bc30a600
  R13: ffff91d7bc30acc0 R14: ffff91d67c123460 R15: 0000000115d7e005
  FS:  00007fe8e9ffb700(0000) GS:ffff91d90fb00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000000 CR3: 000000029f15a001 CR4: 00000000001726e0
  Call Trace:
   kvm_pdptr_read+0x3a/0x40 [kvm]
   paging64_walk_addr_generic+0x327/0x6a0 [kvm]
   paging64_gva_to_gpa_nested+0x3f/0xb0 [kvm]
   kvm_fetch_guest_virt+0x4c/0xb0 [kvm]
   __do_insn_fetch_bytes+0x11a/0x1f0 [kvm]
   x86_decode_insn+0x787/0x1490 [kvm]
   x86_decode_emulated_instruction+0x58/0x1e0 [kvm]
   x86_emulate_instruction+0x122/0x4f0 [kvm]
   vmx_handle_exit+0x120/0x660 [kvm_intel]
   kvm_arch_vcpu_ioctl_run+0xe25/0x1cb0 [kvm]
   kvm_vcpu_ioctl+0x211/0x5a0 [kvm]
   __x64_sys_ioctl+0x83/0xb0
   do_syscall_64+0x40/0xb0
   entry_SYSCALL_64_after_hwframe+0x44/0xae

Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: stable@vger.kernel.org
Fixes: bf627a9288 ("x86/kvm/mmu: check if MMU reconfiguration is needed in init_kvm_nested_mmu()")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210610220026.1364486-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-11 11:54:49 -04:00
Wanpeng Li
dfdc0a714d KVM: X86: Fix x86_emulator slab cache leak
Commit c9b8b07cde (KVM: x86: Dynamically allocate per-vCPU emulation context)
tries to allocate per-vCPU emulation context dynamically, however, the
x86_emulator slab cache is still exiting after the kvm module is unload
as below after destroying the VM and unloading the kvm module.

grep x86_emulator /proc/slabinfo
x86_emulator          36     36   2672   12    8 : tunables    0    0    0 : slabdata      3      3      0

This patch fixes this slab cache leak by destroying the x86_emulator slab cache
when the kvm module is unloaded.

Fixes: c9b8b07cde (KVM: x86: Dynamically allocate per-vCPU emulation context)
Cc: stable@vger.kernel.org
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1623387573-5969-1-git-send-email-wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-11 11:53:48 -04:00
Alper Gun
934002cd66 KVM: SVM: Call SEV Guest Decommission if ASID binding fails
Send SEV_CMD_DECOMMISSION command to PSP firmware if ASID binding
fails. If a failure happens after  a successful LAUNCH_START command,
a decommission command should be executed. Otherwise, guest context
will be unfreed inside the AMD SP. After the firmware will not have
memory to allocate more SEV guest context, LAUNCH_START command will
begin to fail with SEV_RET_RESOURCE_LIMIT error.

The existing code calls decommission inside sev_unbind_asid, but it is
not called if a failure happens before guest activation succeeds. If
sev_bind_asid fails, decommission is never called. PSP firmware has a
limit for the number of guests. If sev_asid_binding fails many times,
PSP firmware will not have resources to create another guest context.

Cc: stable@vger.kernel.org
Fixes: 59414c9892 ("KVM: SVM: Add support for KVM_SEV_LAUNCH_START command")
Reported-by: Peter Gonda <pgonda@google.com>
Signed-off-by: Alper Gun <alpergun@google.com>
Reviewed-by: Marc Orr <marcorr@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210610174604.2554090-1-alpergun@google.com>
2021-06-11 11:52:48 -04:00
Sean Christopherson
78fcb2c91a KVM: x86: Immediately reset the MMU context when the SMM flag is cleared
Immediately reset the MMU context when the vCPU's SMM flag is cleared so
that the SMM flag in the MMU role is always synchronized with the vCPU's
flag.  If RSM fails (which isn't correctly emulated), KVM will bail
without calling post_leave_smm() and leave the MMU in a bad state.

The bad MMU role can lead to a NULL pointer dereference when grabbing a
shadow page's rmap for a page fault as the initial lookups for the gfn
will happen with the vCPU's SMM flag (=0), whereas the rmap lookup will
use the shadow page's SMM flag, which comes from the MMU (=1).  SMM has
an entirely different set of memslots, and so the initial lookup can find
a memslot (SMM=0) and then explode on the rmap memslot lookup (SMM=1).

  general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
  KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
  CPU: 1 PID: 8410 Comm: syz-executor382 Not tainted 5.13.0-rc5-syzkaller #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  RIP: 0010:__gfn_to_rmap arch/x86/kvm/mmu/mmu.c:935 [inline]
  RIP: 0010:gfn_to_rmap+0x2b0/0x4d0 arch/x86/kvm/mmu/mmu.c:947
  Code: <42> 80 3c 20 00 74 08 4c 89 ff e8 f1 79 a9 00 4c 89 fb 4d 8b 37 44
  RSP: 0018:ffffc90000ffef98 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffff888015b9f414 RCX: ffff888019669c40
  RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
  RBP: 0000000000000001 R08: ffffffff811d9cdb R09: ffffed10065a6002
  R10: ffffed10065a6002 R11: 0000000000000000 R12: dffffc0000000000
  R13: 0000000000000003 R14: 0000000000000001 R15: 0000000000000000
  FS:  000000000124b300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000000 CR3: 0000000028e31000 CR4: 00000000001526e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   rmap_add arch/x86/kvm/mmu/mmu.c:965 [inline]
   mmu_set_spte+0x862/0xe60 arch/x86/kvm/mmu/mmu.c:2604
   __direct_map arch/x86/kvm/mmu/mmu.c:2862 [inline]
   direct_page_fault+0x1f74/0x2b70 arch/x86/kvm/mmu/mmu.c:3769
   kvm_mmu_do_page_fault arch/x86/kvm/mmu.h:124 [inline]
   kvm_mmu_page_fault+0x199/0x1440 arch/x86/kvm/mmu/mmu.c:5065
   vmx_handle_exit+0x26/0x160 arch/x86/kvm/vmx/vmx.c:6122
   vcpu_enter_guest+0x3bdd/0x9630 arch/x86/kvm/x86.c:9428
   vcpu_run+0x416/0xc20 arch/x86/kvm/x86.c:9494
   kvm_arch_vcpu_ioctl_run+0x4e8/0xa40 arch/x86/kvm/x86.c:9722
   kvm_vcpu_ioctl+0x70f/0xbb0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3460
   vfs_ioctl fs/ioctl.c:51 [inline]
   __do_sys_ioctl fs/ioctl.c:1069 [inline]
   __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:1055
   do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47
   entry_SYSCALL_64_after_hwframe+0x44/0xae
  RIP: 0033:0x440ce9

Cc: stable@vger.kernel.org
Reported-by: syzbot+fb0b6a7e8713aeb0319c@syzkaller.appspotmail.com
Fixes: 9ec19493fb ("KVM: x86: clear SMM flags before loading state while leaving SMM")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210609185619.992058-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-10 09:21:12 -04:00
Gustavo A. R. Silva
551912d286 KVM: x86: Fix fall-through warnings for Clang
In preparation to enable -Wimplicit-fallthrough for Clang, fix a couple
of warnings by explicitly adding break statements instead of just letting
the code fall through to the next case.

Link: https://github.com/KSPP/linux/issues/115
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Message-Id: <20210528200756.GA39320@embeddedor>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-10 07:48:45 -04:00
ChenXiaoSong
02ffbe6351 KVM: SVM: fix doc warnings
Fix kernel-doc warnings:

arch/x86/kvm/svm/avic.c:233: warning: Function parameter or member 'activate' not described in 'avic_update_access_page'
arch/x86/kvm/svm/avic.c:233: warning: Function parameter or member 'kvm' not described in 'avic_update_access_page'
arch/x86/kvm/svm/avic.c:781: warning: Function parameter or member 'e' not described in 'get_pi_vcpu_info'
arch/x86/kvm/svm/avic.c:781: warning: Function parameter or member 'kvm' not described in 'get_pi_vcpu_info'
arch/x86/kvm/svm/avic.c:781: warning: Function parameter or member 'svm' not described in 'get_pi_vcpu_info'
arch/x86/kvm/svm/avic.c:781: warning: Function parameter or member 'vcpu_info' not described in 'get_pi_vcpu_info'
arch/x86/kvm/svm/avic.c:1009: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst

Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com>
Message-Id: <20210609122217.2967131-1-chenxiaosong2@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-10 07:46:54 -04:00
CodyYao-oc
a8383dfb21 x86/nmi_watchdog: Fix old-style NMI watchdog regression on old Intel CPUs
The following commit:

   3a4ac121c2 ("x86/perf: Add hardware performance events support for Zhaoxin CPU.")

Got the old-style NMI watchdog logic wrong and broke it for basically every
Intel CPU where it was active. Which is only truly old CPUs, so few people noticed.

On CPUs with perf events support we turn off the old-style NMI watchdog, so it
was pretty pointless to add the logic for X86_VENDOR_ZHAOXIN to begin with ... :-/

Anyway, the fix is to restore the old logic and add a 'break'.

[ mingo: Wrote a new changelog. ]

Fixes: 3a4ac121c2 ("x86/perf: Add hardware performance events support for Zhaoxin CPU.")
Signed-off-by: CodyYao-oc <CodyYao-oc@zhaoxin.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210607025335.9643-1-CodyYao-oc@zhaoxin.com
2021-06-10 10:04:40 +02:00
Thomas Gleixner
efa1655049 x86/fpu: Reset state for all signal restore failures
If access_ok() or fpregs_soft_set() fails in __fpu__restore_sig() then the
function just returns but does not clear the FPU state as it does for all
other fatal failures.

Clear the FPU state for these failures as well.

Fixes: 72a671ced6 ("x86, fpu: Unify signal handling code paths for x86 and x86_64 kernels")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/87mtryyhhz.ffs@nanos.tec.linutronix.de
2021-06-10 08:04:24 +02:00
Jim Mattson
218bf772bd kvm: LAPIC: Restore guard to prevent illegal APIC register access
Per the SDM, "any access that touches bytes 4 through 15 of an APIC
register may cause undefined behavior and must not be executed."
Worse, such an access in kvm_lapic_reg_read can result in a leak of
kernel stack contents. Prior to commit 01402cf810 ("kvm: LAPIC:
write down valid APIC registers"), such an access was explicitly
disallowed. Restore the guard that was removed in that commit.

Fixes: 01402cf810 ("kvm: LAPIC: write down valid APIC registers")
Signed-off-by: Jim Mattson <jmattson@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Message-Id: <20210602205224.3189316-1-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-09 17:25:37 -04:00
Linus Torvalds
2f673816b2 Bugfixes, including a TLB flush fix that affects processors
without nested page tables.
 -----BEGIN PGP SIGNATURE-----
 
 iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAmDAVpQUHHBib256aW5p
 QHJlZGhhdC5jb20ACgkQv/vSX3jHroNkOgf9F97eFxAdod3/wbW9EbsUPR5bMTLE
 +R6Hmvw+yCm/W2cycVGdCSh1BEKNuZN/XfHln2cYVfVr6ndog58A4Y0urFAhTROv
 IHs8TCA5biQitoZ716l88ExOitnqJiSmMhGex969+zm1Lb9MQo1KA/zxERlqCi3s
 Pfcxb6I8VbD9LEb6NaQdDgQoslJo1tzhe9gGYAYrpMOZujpj1RPeIOZIfeII0MP/
 g14/JSar8cXc9QJ6zbiKn8HhpmzGJnaIsyFFL2RMIBlKvxsnpOU6VmisLTL9407o
 P246Vq59BM8pdRCVUW9W9hLr2ho8lmi+ZYXASCm+qfn8cLaHyRCqSK56ZQ==
 =nW43
 -----END PGP SIGNATURE-----

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:
 "Bugfixes, including a TLB flush fix that affects processors without
  nested page tables"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  kvm: fix previous commit for 32-bit builds
  kvm: avoid speculation-based attacks from out-of-range memslot accesses
  KVM: x86: Unload MMU on guest TLB flush if TDP disabled to force MMU sync
  KVM: x86: Ensure liveliness of nested VM-Enter fail tracepoint message
  selftests: kvm: Add support for customized slot0 memory size
  KVM: selftests: introduce P47V64 for s390x
  KVM: x86: Ensure PV TLB flush tracepoint reflects KVM behavior
  KVM: X86: MMU: Use the correct inherited permissions to get shadow page
  KVM: LAPIC: Write 0 to TMICT should also cancel vmx-preemption timer
  KVM: SVM: Fix SEV SEND_START session length & SEND_UPDATE_DATA query length after commit 238eca821c
2021-06-09 13:09:57 -07:00
Thomas Gleixner
510b80a6a0 x86/pkru: Write hardware init value to PKRU when xstate is init
When user space brings PKRU into init state, then the kernel handling is
broken:

  T1 user space
     xsave(state)
     state.header.xfeatures &= ~XFEATURE_MASK_PKRU;
     xrstor(state)

  T1 -> kernel
     schedule()
       XSAVE(S) -> T1->xsave.header.xfeatures[PKRU] == 0
       T1->flags |= TIF_NEED_FPU_LOAD;

       wrpkru();

     schedule()
       ...
       pk = get_xsave_addr(&T1->fpu->state.xsave, XFEATURE_PKRU);
       if (pk)
	 wrpkru(pk->pkru);
       else
	 wrpkru(DEFAULT_PKRU);

Because the xfeatures bit is 0 and therefore the value in the xsave
storage is not valid, get_xsave_addr() returns NULL and switch_to()
writes the default PKRU. -> FAIL #1!

So that wrecks any copy_to/from_user() on the way back to user space
which hits memory which is protected by the default PKRU value.

Assumed that this does not fail (pure luck) then T1 goes back to user
space and because TIF_NEED_FPU_LOAD is set it ends up in

  switch_fpu_return()
      __fpregs_load_activate()
        if (!fpregs_state_valid()) {
  	 load_XSTATE_from_task();
        }

But if nothing touched the FPU between T1 scheduling out and back in,
then the fpregs_state is still valid which means switch_fpu_return()
does nothing and just clears TIF_NEED_FPU_LOAD. Back to user space with
DEFAULT_PKRU loaded. -> FAIL #2!

The fix is simple: if get_xsave_addr() returns NULL then set the
PKRU value to 0 instead of the restrictive default PKRU value in
init_pkru_value.

 [ bp: Massage in minor nitpicks from folks. ]

Fixes: 0cecca9d03 ("x86/fpu: Eager switch PKRU state")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Rik van Riel <riel@surriel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20210608144346.045616965@linutronix.de
2021-06-09 12:12:45 +02:00
Thomas Gleixner
12f7764ac6 x86/process: Check PF_KTHREAD and not current->mm for kernel threads
switch_fpu_finish() checks current->mm as indicator for kernel threads.
That's wrong because kernel threads can temporarily use a mm of a user
process via kthread_use_mm().

Check the task flags for PF_KTHREAD instead.

Fixes: 0cecca9d03 ("x86/fpu: Eager switch PKRU state")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Rik van Riel <riel@surriel.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20210608144345.912645927@linutronix.de
2021-06-09 10:39:04 +02:00
Andy Lutomirski
d8778e393a x86/fpu: Invalidate FPU state after a failed XRSTOR from a user buffer
Both Intel and AMD consider it to be architecturally valid for XRSTOR to
fail with #PF but nonetheless change the register state.  The actual
conditions under which this might occur are unclear [1], but it seems
plausible that this might be triggered if one sibling thread unmaps a page
and invalidates the shared TLB while another sibling thread is executing
XRSTOR on the page in question.

__fpu__restore_sig() can execute XRSTOR while the hardware registers
are preserved on behalf of a different victim task (using the
fpu_fpregs_owner_ctx mechanism), and, in theory, XRSTOR could fail but
modify the registers.

If this happens, then there is a window in which __fpu__restore_sig()
could schedule out and the victim task could schedule back in without
reloading its own FPU registers. This would result in part of the FPU
state that __fpu__restore_sig() was attempting to load leaking into the
victim task's user-visible state.

Invalidate preserved FPU registers on XRSTOR failure to prevent this
situation from corrupting any state.

[1] Frequent readers of the errata lists might imagine "complex
    microarchitectural conditions".

Fixes: 1d731e731c ("x86/fpu: Add a fastpath to __fpu__restore_sig()")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Rik van Riel <riel@surriel.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20210608144345.758116583@linutronix.de
2021-06-09 09:49:38 +02:00
Thomas Gleixner
484cea4f36 x86/fpu: Prevent state corruption in __fpu__restore_sig()
The non-compacted slowpath uses __copy_from_user() and copies the entire
user buffer into the kernel buffer, verbatim.  This means that the kernel
buffer may now contain entirely invalid state on which XRSTOR will #GP.
validate_user_xstate_header() can detect some of that corruption, but that
leaves the onus on callers to clear the buffer.

Prior to XSAVES support, it was possible just to reinitialize the buffer,
completely, but with supervisor states that is not longer possible as the
buffer clearing code split got it backwards. Fixing that is possible but
not corrupting the state in the first place is more robust.

Avoid corruption of the kernel XSAVE buffer by using copy_user_to_xstate()
which validates the XSAVE header contents before copying the actual states
to the kernel. copy_user_to_xstate() was previously only called for
compacted-format kernel buffers, but it works for both compacted and
non-compacted forms.

Using it for the non-compacted form is slower because of multiple
__copy_from_user() operations, but that cost is less important than robust
code in an already slow path.

[ Changelog polished by Dave Hansen ]

Fixes: b860eb8dce ("x86/fpu/xstate: Define new functions for clearing fpregs and xstates")
Reported-by: syzbot+2067e764dbcd10721e2e@syzkaller.appspotmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Rik van Riel <riel@surriel.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20210608144345.611833074@linutronix.de
2021-06-09 09:28:21 +02:00
Lai Jiangshan
b53e84eed0 KVM: x86: Unload MMU on guest TLB flush if TDP disabled to force MMU sync
When using shadow paging, unload the guest MMU when emulating a guest TLB
flush to ensure all roots are synchronized.  From the guest's perspective,
flushing the TLB ensures any and all modifications to its PTEs will be
recognized by the CPU.

Note, unloading the MMU is overkill, but is done to mirror KVM's existing
handling of INVPCID(all) and ensure the bug is squashed.  Future cleanup
can be done to more precisely synchronize roots when servicing a guest
TLB flush.

If TDP is enabled, synchronizing the MMU is unnecessary even if nested
TDP is in play, as a "legacy" TLB flush from L1 does not invalidate L1's
TDP mappings.  For EPT, an explicit INVEPT is required to invalidate
guest-physical mappings; for NPT, guest mappings are always tagged with
an ASID and thus can only be invalidated via the VMCB's ASID control.

This bug has existed since the introduction of KVM_VCPU_FLUSH_TLB.
It was only recently exposed after Linux guests stopped flushing the
local CPU's TLB prior to flushing remote TLBs (see commit 4ce94eabac,
"x86/mm/tlb: Flush remote and local TLBs concurrently"), but is also
visible in Windows 10 guests.

Tested-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Fixes: f38a7b7526 ("KVM: X86: support paravirtualized help for TLB shootdowns")
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
[sean: massaged comment and changelog]
Message-Id: <20210531172256.2908-1-jiangshanlai@gmail.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-08 17:10:21 -04:00
Sean Christopherson
f31500b0d4 KVM: x86: Ensure liveliness of nested VM-Enter fail tracepoint message
Use the __string() machinery provided by the tracing subystem to make a
copy of the string literals consumed by the "nested VM-Enter failed"
tracepoint.  A complete copy is necessary to ensure that the tracepoint
can't outlive the data/memory it consumes and deference stale memory.

Because the tracepoint itself is defined by kvm, if kvm-intel and/or
kvm-amd are built as modules, the memory holding the string literals
defined by the vendor modules will be freed when the module is unloaded,
whereas the tracepoint and its data in the ring buffer will live until
kvm is unloaded (or "indefinitely" if kvm is built-in).

This bug has existed since the tracepoint was added, but was recently
exposed by a new check in tracing to detect exactly this type of bug.

  fmt: '%s%s
  ' current_buffer: ' vmx_dirty_log_t-140127  [003] ....  kvm_nested_vmenter_failed: '
  WARNING: CPU: 3 PID: 140134 at kernel/trace/trace.c:3759 trace_check_vprintf+0x3be/0x3e0
  CPU: 3 PID: 140134 Comm: less Not tainted 5.13.0-rc1-ce2e73ce600a-req #184
  Hardware name: ASUS Q87M-E/Q87M-E, BIOS 1102 03/03/2014
  RIP: 0010:trace_check_vprintf+0x3be/0x3e0
  Code: <0f> 0b 44 8b 4c 24 1c e9 a9 fe ff ff c6 44 02 ff 00 49 8b 97 b0 20
  RSP: 0018:ffffa895cc37bcb0 EFLAGS: 00010282
  RAX: 0000000000000000 RBX: ffffa895cc37bd08 RCX: 0000000000000027
  RDX: 0000000000000027 RSI: 00000000ffffdfff RDI: ffff9766cfad74f8
  RBP: ffffffffc0a041d4 R08: ffff9766cfad74f0 R09: ffffa895cc37bad8
  R10: 0000000000000001 R11: 0000000000000001 R12: ffffffffc0a041d4
  R13: ffffffffc0f4dba8 R14: 0000000000000000 R15: ffff976409f2c000
  FS:  00007f92fa200740(0000) GS:ffff9766cfac0000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000559bd11b0000 CR3: 000000019fbaa002 CR4: 00000000001726e0
  Call Trace:
   trace_event_printf+0x5e/0x80
   trace_raw_output_kvm_nested_vmenter_failed+0x3a/0x60 [kvm]
   print_trace_line+0x1dd/0x4e0
   s_show+0x45/0x150
   seq_read_iter+0x2d5/0x4c0
   seq_read+0x106/0x150
   vfs_read+0x98/0x180
   ksys_read+0x5f/0xe0
   do_syscall_64+0x40/0xb0
   entry_SYSCALL_64_after_hwframe+0x44/0xae

Cc: Steven Rostedt <rostedt@goodmis.org>
Fixes: 380e0055bc ("KVM: nVMX: trace nested VM-Enter failures detected by H/W")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Message-Id: <20210607175748.674002-1-seanjc@google.com>
2021-06-08 13:30:49 -04:00
Lai Jiangshan
af3511ff7f KVM: x86: Ensure PV TLB flush tracepoint reflects KVM behavior
In record_steal_time(), st->preempted is read twice, and
trace_kvm_pv_tlb_flush() might output result inconsistent if
kvm_vcpu_flush_tlb_guest() see a different st->preempted later.

It is a very trivial problem and hardly has actual harm and can be
avoided by reseting and reading st->preempted in atomic way via xchg().

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>

Message-Id: <20210531174628.10265-1-jiangshanlai@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-08 13:15:20 -04:00