Commit Graph

798426 Commits

Author SHA1 Message Date
Punit Agrawal
35a6396619 KVM: arm64: Update age handlers to support PUD hugepages
In preparation for creating larger hugepages at Stage 2, add support
to the age handling notifiers for PUD hugepages when encountered.

Provide trivial helpers for arm32 to allow sharing code.

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
[ Replaced BUG() => WARN_ON(1) for arm32 PUD helpers ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 15:14:48 +00:00
Punit Agrawal
eb3f0624ea KVM: arm64: Support handling access faults for PUD hugepages
In preparation for creating larger hugepages at Stage 2, extend the
access fault handling at Stage 2 to support PUD hugepages when
encountered.

Provide trivial helpers for arm32 to allow sharing of code.

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
[ Replaced BUG() => WARN_ON(1) in PUD helpers ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 15:14:48 +00:00
Punit Agrawal
86d1c55ea6 KVM: arm64: Support PUD hugepage in stage2_is_exec()
In preparation for creating PUD hugepages at stage 2, add support for
detecting execute permissions on PUD page table entries. Faults due to
lack of execute permissions on page table entries is used to perform
i-cache invalidation on first execute.

Provide trivial implementations of arm32 helpers to allow sharing of
code.

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
[ Replaced BUG() => WARN_ON(1) in arm32 PUD helpers ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 15:14:48 +00:00
Punit Agrawal
4ea5af5311 KVM: arm64: Support dirty page tracking for PUD hugepages
In preparation for creating PUD hugepages at stage 2, add support for
write protecting PUD hugepages when they are encountered. Write
protecting guest tables is used to track dirty pages when migrating
VMs.

Also, provide trivial implementations of required kvm_s2pud_* helpers
to allow sharing of code with arm32.

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
[ Replaced BUG() => WARN_ON() in arm32 pud helpers ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 15:14:47 +00:00
Punit Agrawal
f8df73388e KVM: arm/arm64: Introduce helpers to manipulate page table entries
Introduce helpers to abstract architectural handling of the conversion
of pfn to page table entries and marking a PMD page table entry as a
block entry.

The helpers are introduced in preparation for supporting PUD hugepages
at stage 2 - which are supported on arm64 but do not exist on arm.

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 15:14:47 +00:00
Punit Agrawal
6396b852e4 KVM: arm/arm64: Re-factor setting the Stage 2 entry to exec on fault
Stage 2 fault handler marks a page as executable if it is handling an
execution fault or if it was a permission fault in which case the
executable bit needs to be preserved.

The logic to decide if the page should be marked executable is
duplicated for PMD and PTE entries. To avoid creating another copy
when support for PUD hugepages is introduced refactor the code to
share the checks needed to mark a page table entry as executable.

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 15:14:47 +00:00
Punit Agrawal
3f58bf6345 KVM: arm/arm64: Share common code in user_mem_abort()
The code for operations such as marking the pfn as dirty, and
dcache/icache maintenance during stage 2 fault handling is duplicated
between normal pages and PMD hugepages.

Instead of creating another copy of the operations when we introduce
PUD hugepages, let's share them across the different pagesizes.

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 15:14:46 +00:00
Christoffer Dall
60c3ab30d8 KVM: arm/arm64: vgic-v2: Set active_source to 0 when restoring state
When restoring the active state from userspace, we don't know which CPU
was the source for the active state, and this is not architecturally
exposed in any of the register state.

Set the active_source to 0 in this case.  In the future, we can expand
on this and exposse the information as additional information to
userspace for GICv2 if anyone cares.

Cc: stable@vger.kernel.org
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 15:14:46 +00:00
Mark Rutland
d1878af3a5 KVM: arm/arm64: Log PSTATE for unhandled sysregs
When KVM traps an unhandled sysreg/coproc access from a guest, it logs
the guest PC. To aid debugging, it would be helpful to know which
exception level the trap came from, along with other PSTATE/CPSR bits,
so let's log the PSTATE/CPSR too.

Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 15:14:45 +00:00
Christoffer Dall
fb544d1ca6 KVM: arm/arm64: Fix VMID alloc race by reverting to lock-less
We recently addressed a VMID generation race by introducing a read/write
lock around accesses and updates to the vmid generation values.

However, kvm_arch_vcpu_ioctl_run() also calls need_new_vmid_gen() but
does so without taking the read lock.

As far as I can tell, this can lead to the same kind of race:

  VM 0, VCPU 0			VM 0, VCPU 1
  ------------			------------
  update_vttbr (vmid 254)
  				update_vttbr (vmid 1) // roll over
				read_lock(kvm_vmid_lock);
				force_vm_exit()
  local_irq_disable
  need_new_vmid_gen == false //because vmid gen matches

  enter_guest (vmid 254)
  				kvm_arch.vttbr = <PGD>:<VMID 1>
				read_unlock(kvm_vmid_lock);

  				enter_guest (vmid 1)

Which results in running two VCPUs in the same VM with different VMIDs
and (even worse) other VCPUs from other VMs could now allocate clashing
VMID 254 from the new generation as long as VCPU 0 is not exiting.

Attempt to solve this by making sure vttbr is updated before another CPU
can observe the updated VMID generation.

Cc: stable@vger.kernel.org
Fixes: f0cf47d939 "KVM: arm/arm64: Close VMID generation race"
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 15:14:45 +00:00
Mark Rutland
bd7d95cafb arm64: KVM: Consistently advance singlestep when emulating instructions
When we emulate a guest instruction, we don't advance the hardware
singlestep state machine, and thus the guest will receive a software
step exception after a next instruction which is not emulated by the
host.

We bodge around this in an ad-hoc fashion. Sometimes we explicitly check
whether userspace requested a single step, and fake a debug exception
from within the kernel. Other times, we advance the HW singlestep state
rely on the HW to generate the exception for us. Thus, the observed step
behaviour differs for host and guest.

Let's make this simpler and consistent by always advancing the HW
singlestep state machine when we skip an instruction. Thus we can rely
on the hardware to generate the singlestep exception for us, and never
need to explicitly check for an active-pending step, nor do we need to
fake a debug exception from the guest.

Cc: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 14:11:37 +00:00
Mark Rutland
0d640732db arm64: KVM: Skip MMIO insn after emulation
When we emulate an MMIO instruction, we advance the CPU state within
decode_hsr(), before emulating the instruction effects.

Having this logic in decode_hsr() is opaque, and advancing the state
before emulation is problematic. It gets in the way of applying
consistent single-step logic, and it prevents us from being able to fail
an MMIO instruction with a synchronous exception.

Clean this up by only advancing the CPU state *after* the effects of the
instruction are emulated.

Cc: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 14:10:36 +00:00
Michael Mueller
7aedd9d48f KVM: s390: fix kmsg component kvm-s390
Relocate #define statement for kvm related kernel messages
before the include of printk to become effective.

Signed-off-by: Michael Mueller <mimu@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2018-12-18 10:18:27 +01:00
Michael Mueller
308c3e6673 KVM: s390: unregister debug feature on failing arch init
Make sure the debug feature and its allocated resources get
released upon unsuccessful architecture initialization.

A related indication of the issue will be reported as kernel
message.

Signed-off-by: Michael Mueller <mimu@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-Id: <20181130143215.69496-2-mimu@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2018-12-18 10:18:27 +01:00
Suraj Jitindar Singh
95d386c2d2 KVM: PPC: Book3S HV: Allow passthrough of an emulated device to an L3 guest
Previously when a device was being emulated by an L1 guest for an L2
guest, that device couldn't then be passed through to an L3 guest. This
was because the L1 guest had no method for accessing L3 memory.

The hcall H_COPY_TOFROM_GUEST provides this access. Thus this setup for
passthrough can now be allowed.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-12-17 11:33:50 +11:00
Suraj Jitindar Singh
6ff887b8bd KVM: PPC: Book3S: Introduce new hcall H_COPY_TOFROM_GUEST to access quadrants 1 & 2
A guest cannot access quadrants 1 or 2 as this would result in an
exception. Thus introduce the hcall H_COPY_TOFROM_GUEST to be used by a
guest when it wants to perform an access to quadrants 1 or 2, for
example when it wants to access memory for one of its nested guests.

Also provide an implementation for the kvm-hv module.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-12-17 11:33:50 +11:00
Suraj Jitindar Singh
873db2cd9a KVM: PPC: Book3S HV: Allow passthrough of an emulated device to an L2 guest
Allow for a device which is being emulated at L0 (the host) for an L1
guest to be passed through to a nested (L2) guest.

The existing kvmppc_hv_emulate_mmio function can be used here. The main
challenge is that for a load the result must be stored into the L2 gpr,
not an L1 gpr as would normally be the case after going out to qemu to
complete the operation. This presents a challenge as at this point the
L2 gpr state has been written back into L1 memory.

To work around this we store the address in L1 memory of the L2 gpr
where the result of the load is to be stored and use the new io_gpr
value KVM_MMIO_REG_NESTED_GPR to indicate that this is a nested load for
which completion must be done when returning back into the kernel. Then
in kvmppc_complete_mmio_load() the resultant value is written into L1
memory at the location of the indicated L2 gpr.

Note that we don't currently let an L1 guest emulate a device for an L2
guest which is then passed through to an L3 guest.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-12-17 11:33:50 +11:00
Suraj Jitindar Singh
cc6929cc84 KVM: PPC: Update kvmppc_st and kvmppc_ld to use quadrants
The functions kvmppc_st and kvmppc_ld are used to access guest memory
from the host using a guest effective address. They do so by translating
through the process table to obtain a guest real address and then using
kvm_read_guest or kvm_write_guest to make the access with the guest real
address.

This method of access however only works for L1 guests and will give the
incorrect results for a nested guest.

We can however use the store_to_eaddr and load_from_eaddr kvmppc_ops to
perform the access for a nested guesti (and a L1 guest). So attempt this
method first and fall back to the old method if this fails and we aren't
running a nested guest.

At this stage there is no fall back method to perform the access for a
nested guest and this is left as a future improvement. For now we will
return to the nested guest and rely on the fact that a translation
should be faulted in before retrying the access.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-12-17 11:33:50 +11:00
Suraj Jitindar Singh
dceadcf91b KVM: PPC: Add load_from_eaddr and store_to_eaddr to the kvmppc_ops struct
The kvmppc_ops struct is used to store function pointers to kvm
implementation specific functions.

Introduce two new functions load_from_eaddr and store_to_eaddr to be
used to load from and store to a guest effective address respectively.

Also implement these for the kvm-hv module. If we are using the radix
mmu then we can call the functions to access quadrant 1 and 2.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-12-17 11:33:50 +11:00
Suraj Jitindar Singh
d7b4561522 KVM: PPC: Book3S HV: Implement functions to access quadrants 1 & 2
The POWER9 radix mmu has the concept of quadrants. The quadrant number
is the two high bits of the effective address and determines the fully
qualified address to be used for the translation. The fully qualified
address consists of the effective lpid, the effective pid and the
effective address. This gives then 4 possible quadrants 0, 1, 2, and 3.

When accessing these quadrants the fully qualified address is obtained
as follows:

Quadrant		| Hypervisor		| Guest
--------------------------------------------------------------------------
			| EA[0:1] = 0b00	| EA[0:1] = 0b00
0			| effLPID = 0		| effLPID = LPIDR
			| effPID  = PIDR	| effPID  = PIDR
--------------------------------------------------------------------------
			| EA[0:1] = 0b01	|
1			| effLPID = LPIDR	| Invalid Access
			| effPID  = PIDR	|
--------------------------------------------------------------------------
			| EA[0:1] = 0b10	|
2			| effLPID = LPIDR	| Invalid Access
			| effPID  = 0		|
--------------------------------------------------------------------------
			| EA[0:1] = 0b11	| EA[0:1] = 0b11
3			| effLPID = 0		| effLPID = LPIDR
			| effPID  = 0		| effPID  = 0
--------------------------------------------------------------------------

In the Guest;
Quadrant 3 is normally used to address the operating system since this
uses effPID=0 and effLPID=LPIDR, meaning the PID register doesn't need to
be switched.
Quadrant 0 is normally used to address user space since the effLPID and
effPID are taken from the corresponding registers.

In the Host;
Quadrant 0 and 3 are used as above, however the effLPID is always 0 to
address the host.

Quadrants 1 and 2 can be used by the host to address guest memory using
a guest effective address. Since the effLPID comes from the LPID register,
the host loads the LPID of the guest it would like to access (and the
PID of the process) and can perform accesses to a guest effective
address.

This means quadrant 1 can be used to address the guest user space and
quadrant 2 can be used to address the guest operating system from the
hypervisor, using a guest effective address.

Access to the quadrants can cause a Hypervisor Data Storage Interrupt
(HDSI) due to being unable to perform partition scoped translation.
Previously this could only be generated from a guest and so the code
path expects us to take the KVM trampoline in the interrupt handler.
This is no longer the case so we modify the handler to call
bad_page_fault() to check if we were expecting this fault so we can
handle it gracefully and just return with an error code. In the hash mmu
case we still raise an unknown exception since quadrants aren't defined
for the hash mmu.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-12-17 11:33:50 +11:00
Suraj Jitindar Singh
d232afebf9 KVM: PPC: Book3S HV: Add function kvmhv_vcpu_is_radix()
There exists a function kvm_is_radix() which is used to determine if a
kvm instance is using the radix mmu. However this only applies to the
first level (L1) guest. Add a function kvmhv_vcpu_is_radix() which can
be used to determine if the current execution context of the vcpu is
radix, accounting for if the vcpu is running a nested guest.

Currently all nested guests must be radix but this may change in the
future.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-12-17 11:33:49 +11:00
Suraj Jitindar Singh
693ac10a88 KVM: PPC: Book3S: Only report KVM_CAP_SPAPR_TCE_VFIO on powernv machines
The kvm capability KVM_CAP_SPAPR_TCE_VFIO is used to indicate the
availability of in kernel tce acceleration for vfio. However it is
currently the case that this is only available on a powernv machine,
not for a pseries machine.

Thus make this capability dependent on having the cpu feature
CPU_FTR_HVMODE.

[paulus@ozlabs.org - fixed compilation for Book E.]

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-12-17 11:33:49 +11:00
Paul Mackerras
5af3e9d06d KVM: PPC: Book3S HV: Flush guest mappings when turning dirty tracking on/off
This adds code to flush the partition-scoped page tables for a radix
guest when dirty tracking is turned on or off for a memslot.  Only the
guest real addresses covered by the memslot are flushed.  The reason
for this is to get rid of any 2M PTEs in the partition-scoped page
tables that correspond to host transparent huge pages, so that page
dirtiness is tracked at a system page (4k or 64k) granularity rather
than a 2M granularity.  The page tables are also flushed when turning
dirty tracking off so that the memslot's address space can be
repopulated with THPs if possible.

To do this, we add a new function kvmppc_radix_flush_memslot().  Since
this does what's needed for kvmppc_core_flush_memslot_hv() on a radix
guest, we now make kvmppc_core_flush_memslot_hv() call the new
kvmppc_radix_flush_memslot() rather than calling kvm_unmap_radix()
for each page in the memslot.  This has the effect of fixing a bug in
that kvmppc_core_flush_memslot_hv() was previously calling
kvm_unmap_radix() without holding the kvm->mmu_lock spinlock, which
is required to be held.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-12-17 10:58:51 +11:00
Paul Mackerras
c43c3a8683 KVM: PPC: Book3S HV: Cleanups - constify memslots, fix comments
This adds 'const' to the declarations for the struct kvm_memory_slot
pointer parameters of some functions, which will make it possible to
call those functions from kvmppc_core_commit_memory_region_hv()
in the next patch.

This also fixes some comments about locking.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-12-17 10:58:43 +11:00
Paul Mackerras
f460f6791a KVM: PPC: Book3S HV: Map single pages when doing dirty page logging
For radix guests, this makes KVM map guest memory as individual pages
when dirty page logging is enabled for the memslot corresponding to the
guest real address.  Having a separate partition-scoped PTE for each
system page mapped to the guest means that we have a separate dirty
bit for each page, thus making the reported dirty bitmap more accurate.
Without this, if part of guest memory is backed by transparent huge
pages, the dirty status is reported at a 2MB granularity rather than
a 64kB (or 4kB) granularity for that part, causing userspace to have
to transmit more data when migrating the guest.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-12-17 10:58:33 +11:00
Bharata B Rao
f032b73459 KVM: PPC: Pass change type down to memslot commit function
Currently, kvm_arch_commit_memory_region() gets called with a
parameter indicating what type of change is being made to the memslot,
but it doesn't pass it down to the platform-specific memslot commit
functions.  This adds the `change' parameter to the lower-level
functions so that they can use it in future.

[paulus@ozlabs.org - fix book E also.]

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-12-17 10:57:27 +11:00
Paolo Bonzini
5132411985 kvm: selftests: ucall: improve ucall placement in memory, fix unsigned comparison
Based on a patch by Andrew Jones.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 18:00:08 +01:00
Marc Orr
b666a4b697 kvm: x86: Dynamically allocate guest_fpu
Previously, the guest_fpu field was embedded in the kvm_vcpu_arch
struct. Unfortunately, the field is quite large, (e.g., 4352 bytes on my
current setup). This bloats the kvm_vcpu_arch struct for x86 into an
order 3 memory allocation, which can become a problem on overcommitted
machines. Thus, this patch moves the fpu state outside of the
kvm_vcpu_arch struct.

With this patch applied, the kvm_vcpu_arch struct is reduced to 15168
bytes for vmx on my setup when building the kernel with kvmconfig.

Suggested-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Marc Orr <marcorr@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 18:00:08 +01:00
Marc Orr
240c35a378 kvm: x86: Use task structs fpu field for user
Previously, x86's instantiation of 'struct kvm_vcpu_arch' added an fpu
field to save/restore fpu-related architectural state, which will differ
from kvm's fpu state. However, this is redundant to the 'struct fpu'
field, called fpu, embedded in the task struct, via the thread field.
Thus, this patch removes the user_fpu field from the kvm_vcpu_arch
struct and replaces it with the task struct's fpu field.

This change is significant because the fpu struct is actually quite
large. For example, on the system used to develop this patch, this
change reduces the size of the vcpu_vmx struct from 23680 bytes down to
19520 bytes, when building the kernel with kvmconfig. This reduction in
the size of the vcpu_vmx struct moves us closer to being able to
allocate the struct at order 2, rather than order 3.

Suggested-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Marc Orr <marcorr@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 18:00:07 +01:00
Krish Sadhukhan
4e445aee96 KVM: nVMX: Move the checks for Guest Non-Register States to a separate helper function
.. to improve readability and maintainability, and to align the code as per
the layout of the checks in chapter "VM Entries" in Intel SDM vol 3C.

Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: Mark Kanda <mark.kanda@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 18:00:06 +01:00
Krish Sadhukhan
254b2f3b0f KVM: nVMX: Move the checks for Host Control Registers and MSRs to a separate helper function
.. to improve readability and maintainability, and to align the code as per
the layout of the checks in chapter "VM Entries" in Intel SDM vol 3C.

Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: Mark Kanda <mark.kanda@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 18:00:06 +01:00
Krish Sadhukhan
5fbf963400 KVM: nVMX: Move the checks for VM-Entry Control Fields to a separate helper function
.. to improve readability and maintainability, and to align the code as per
the layout of the checks in chapter "VM Entries" in Intel SDM vol 3C.

Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: Mark Kanda <mark.kanda@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 18:00:05 +01:00
Krish Sadhukhan
61446ba75e KVM: nVMX: Move the checks for VM-Exit Control Fields to a separate helper function
.. to improve readability and maintainability, and to align the code as per
the layout of the checks in chapter "VM Entries" in Intel SDM vol 3C.

Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: Mark Kanda <mark.kanda@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 18:00:04 +01:00
Sean Christopherson
f9b245e182 KVM: nVMX: Remove param indirection from nested_vmx_check_msr_switch()
Passing the enum and doing an indirect lookup is silly when we can
simply pass the field directly.  Remove the "fast path" code in
nested_vmx_check_msr_switch_controls() as it's now nothing more than a
redundant check.

Remove the debug message rather than continue passing the enum for the
address field.  Having debug messages for the MSRs themselves is useful
as MSR legality is a huge space, whereas messing up a physical address
means the VMM is fundamentally broken.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 18:00:04 +01:00
Krish Sadhukhan
461b4ba4c7 KVM: nVMX: Move the checks for VM-Execution Control Fields to a separate helper function
.. to improve readability and maintainability, and to align the code as per
the layout of the checks in chapter "VM Entries" in Intel SDM vol 3C.

Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: Mark Kanda <mark.kanda@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 18:00:03 +01:00
Krish Sadhukhan
16322a3b5e KVM: nVMX: Prepend "nested_vmx_" to check_vmentry_{pre,post}reqs()
.. as they are used only in nested vmx context.

Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: Mark Kanda <mark.kanda@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 18:00:02 +01:00
Lan Tianyu
53963a70ac KVM/VMX: Check ept_pointer before flushing ept tlb
This patch is to initialize ept_pointer to INVALID_PAGE and check it
before flushing ept tlb. If ept_pointer is invalid, bypass the flush
request.

Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 18:00:02 +01:00
Krish Sadhukhan
a0d4f80344 KVM nVMX: MSRs should not be stored if VM-entry fails during or after loading guest state
According to section "VM-entry Failures During or After Loading Guest State"
in Intel SDM vol 3C,

	"No MSRs are saved into the VM-exit MSR-store area."

when bit 31 of the exit reason is set.

Reported-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Suggested-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 18:00:01 +01:00
Jim Mattson
e53d88af63 kvm: x86: Don't modify MSR_PLATFORM_INFO on vCPU reset
If userspace has provided a different value for this MSR (e.g with the
turbo bits set), the userspace-provided value should survive a vCPU
reset. For backwards compatibility, MSR_PLATFORM_INFO is initialized
in kvm_arch_vcpu_setup.

Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Drew Schmitt <dasch@google.com>
Cc: Abhiroop Dabral <adabral@paloaltonetworks.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 18:00:01 +01:00
Wei Huang
3d82c565a7 kvm: vmx: add cpu into VMX preemption timer bug list
This patch adds Intel "Xeon CPU E3-1220 V2", with CPUID.01H.EAX=0x000306A8,
into the list of known broken CPUs which fail to support VMX preemption
timer. This bug was found while running the APIC timer test of
kvm-unit-test on this specific CPU, even though the errata info can't be
located in the public domain for this CPU.

Signed-off-by: Wei Huang <wei@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 18:00:00 +01:00
Eduardo Habkost
d7b09c827a kvm: x86: Report STIBP on GET_SUPPORTED_CPUID
Months ago, we have added code to allow direct access to MSR_IA32_SPEC_CTRL
to the guest, which makes STIBP available to guests.  This was implemented
by commits d28b387fb7 ("KVM/VMX: Allow direct access to
MSR_IA32_SPEC_CTRL") and b2ac58f905 ("KVM/SVM: Allow direct access to
MSR_IA32_SPEC_CTRL").

However, we never updated GET_SUPPORTED_CPUID to let userspace know that
STIBP can be enabled in CPUID.  Fix that by updating
kvm_cpuid_8000_0008_ebx_x86_features and kvm_cpuid_7_0_edx_x86_features.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 17:59:59 +01:00
Vitaly Kuznetsov
87a8d795b2 x86/hyper-v: Stop caring about EOI for direct stimers
Turns out we over-engineered Direct Mode for stimers a bit: unlike
traditional stimers where we may want to try to re-inject the message upon
EOI, Direct Mode stimers just set the irq in APIC and kvm_apic_set_irq()
fails only when APIC is disabled (see APIC_DM_FIXED case in
__apic_accept_irq()). Remove the redundant part.

Suggested-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 17:59:59 +01:00
Vitaly Kuznetsov
08a800ac25 x86/kvm/hyper-v: avoid open-coding stimer_mark_pending() in kvm_hv_notify_acked_sint()
stimers_pending optimization only helps us to avoid multiple
kvm_make_request() calls. This doesn't happen very often and these
calls are very cheap in the first place, remove open-coded version of
stimer_mark_pending() from kvm_hv_notify_acked_sint().

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 17:59:58 +01:00
Vitaly Kuznetsov
8644f771e0 x86/kvm/hyper-v: direct mode for synthetic timers
Turns out Hyper-V on KVM (as of 2016) will only use synthetic timers
if direct mode is available. With direct mode we notify the guest by
asserting APIC irq instead of sending a SynIC message.

The implementation uses existing vec_bitmap for letting lapic code
know that we're interested in the particular IRQ's EOI request. We assume
that the same APIC irq won't be used by the guest for both direct mode
stimer and as sint source (especially with AutoEOI semantics). It is
unclear how things should be handled if that's not true.

Direct mode is also somewhat less expensive; in my testing
stimer_send_msg() takes not less than 1500 cpu cycles and
stimer_notify_direct() can usually be done in 300-400. WS2016 without
Hyper-V, however, always sticks to non-direct version.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 17:59:57 +01:00
Vitaly Kuznetsov
6a058a1ead x86/kvm/hyper-v: use stimer config definition from hyperv-tlfs.h
As a preparation to implementing Direct Mode for Hyper-V synthetic
timers switch to using stimer config definition from hyperv-tlfs.h.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 17:59:57 +01:00
Vitaly Kuznetsov
0aa67255f5 x86/hyper-v: move synic/stimer control structures definitions to hyperv-tlfs.h
We implement Hyper-V SynIC and synthetic timers in KVM too so there's some
room for code sharing.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 17:59:56 +01:00
Vitaly Kuznetsov
7edcb73433 KVM: selftests: Add hyperv_cpuid test
Add a simple (and stupid) hyperv_cpuid test: check that we got the
expected number of entries with and without Enlightened VMCS enabled
and that all currently reserved fields are zeroed.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 17:59:56 +01:00
Vitaly Kuznetsov
7e50c424f8 KVM: selftests: implement an unchecked version of vcpu_ioctl()
In case we want to test failing ioctls we need an option to not
fail. Following _vcpu_run() precedent implement _vcpu_ioctl().

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 17:59:55 +01:00
Vitaly Kuznetsov
2bc39970e9 x86/kvm/hyper-v: Introduce KVM_GET_SUPPORTED_HV_CPUID
With every new Hyper-V Enlightenment we implement we're forced to add a
KVM_CAP_HYPERV_* capability. While this approach works it is fairly
inconvenient: the majority of the enlightenments we do have corresponding
CPUID feature bit(s) and userspace has to know this anyways to be able to
expose the feature to the guest.

Add KVM_GET_SUPPORTED_HV_CPUID ioctl (backed by KVM_CAP_HYPERV_CPUID, "one
cap to rule them all!") returning all Hyper-V CPUID feature leaves.

Using the existing KVM_GET_SUPPORTED_CPUID doesn't seem to be possible:
Hyper-V CPUID feature leaves intersect with KVM's (e.g. 0x40000000,
0x40000001) and we would probably confuse userspace in case we decide to
return these twice.

KVM_CAP_HYPERV_CPUID's number is interim: we're intended to drop
KVM_CAP_HYPERV_STIMER_DIRECT and use its number instead.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 17:59:54 +01:00
Vitaly Kuznetsov
e2e871ab2f x86/kvm/hyper-v: Introduce nested_get_evmcs_version() helper
The upcoming KVM_GET_SUPPORTED_HV_CPUID ioctl will need to return
Enlightened VMCS version in HYPERV_CPUID_NESTED_FEATURES.EAX when
it was enabled.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 17:59:54 +01:00