Commit Graph

68 Commits

Author SHA1 Message Date
Atish Patra
affa28e4d0 RISC-V: KVM: Introduce ISA extension register
Currently, there is no provision for vmm (qemu-kvm or kvmtool) to
query about multiple-letter ISA extensions. The config register
is only used for base single letter ISA extensions.

A new ISA extension register is added that will allow the vmm
to query about any ISA extension one at a time. It is enabled for
both single letter or multi-letter ISA extensions. The ISA extension
register is useful to if the vmm requires to retrieve/set single
extension while the config register should be used if all the base
ISA extension required to retrieve or set.

For any multi-letter ISA extensions, the new register interface
must be used.

Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-05-20 09:09:20 +05:30
Anup Patel
92e450507d RISC-V: KVM: Cleanup stale TLB entries when host CPU changes
On RISC-V platforms with hardware VMID support, we share same
VMID for all VCPUs of a particular Guest/VM. This means we might
have stale G-stage TLB entries on the current Host CPU due to
some other VCPU of the same Guest which ran previously on the
current Host CPU.

To cleanup stale TLB entries, we simply flush all G-stage TLB
entries by VMID whenever underlying Host CPU changes for a VCPU.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-05-20 09:09:18 +05:30
Anup Patel
13acfec2db RISC-V: KVM: Add remote HFENCE functions based on VCPU requests
The generic KVM has support for VCPU requests which can be used
to do arch-specific work in the run-loop. We introduce remote
HFENCE functions which will internally use VCPU requests instead
of host SBI calls.

Advantages of doing remote HFENCEs as VCPU requests are:
1) Multiple VCPUs of a Guest may be running on different Host CPUs
   so it is not always possible to determine the Host CPU mask for
   doing Host SBI call. For example, when VCPU X wants to do HFENCE
   on VCPU Y, it is possible that VCPU Y is blocked or in user-space
   (i.e. vcpu->cpu < 0).
2) To support nested virtualization, we will be having a separate
   shadow G-stage for each VCPU and a common host G-stage for the
   entire Guest/VM. The VCPU requests based remote HFENCEs helps
   us easily synchronize the common host G-stage and shadow G-stage
   of each VCPU without any additional IPI calls.

This is also a preparatory patch for upcoming nested virtualization
support where we will be having a shadow G-stage page table for
each Guest VCPU.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-05-20 09:09:15 +05:30
Anup Patel
2415e46e3a RISC-V: KVM: Introduce range based local HFENCE functions
Various  __kvm_riscv_hfence_xyz() functions implemented in the
kvm/tlb.S are equivalent to corresponding HFENCE.GVMA instructions
and we don't have range based local HFENCE functions.

This patch provides complete set of local HFENCE functions which
supports range based TLB invalidation and supports HFENCE.VVMA
based functions. This is also a preparatory patch for upcoming
Svinval support in KVM RISC-V.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-05-20 09:09:09 +05:30
Anup Patel
c7fa3c48de RISC-V: KVM: Treat SBI HFENCE calls as NOPs
We should treat SBI HFENCE calls as NOPs until nested virtualization
is supported by KVM RISC-V. This will help us test booting a hypervisor
under KVM RISC-V.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-05-20 09:09:06 +05:30
Anup Patel
b4bbb95ea6 RISC-V: KVM: Add Sv57x4 mode support for G-stage
Latest QEMU supports G-stage Sv57x4 mode so this patch extends KVM
RISC-V G-stage handling to detect and use Sv57x4 mode when available.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-05-20 09:09:04 +05:30
Anup Patel
26708234eb RISC-V: KVM: Use G-stage name for hypervisor page table
The two-stage address translation defined by the RISC-V privileged
specification defines: VS-stage (guest virtual address to guest
physical address) programmed by the Guest OS  and G-stage (guest
physical addree to host physical address) programmed by the
hypervisor.

To align with above terminology, we replace "stage2" with "gstage"
and "Stage2" with "G-stage" name everywhere in KVM RISC-V sources.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-05-20 09:09:01 +05:30
Paolo Bonzini
73331c5d84 Merge branch 'kvm-fixes-for-5.18-rc5' into HEAD
Fixes for (relatively) old bugs, to be merged in both the -rc and next
development trees:

* Fix potential races when walking host page table

* Fix bad user ABI for KVM_EXIT_SYSTEM_EVENT

* Fix shadow page table leak when KVM runs nested
2022-04-29 12:39:34 -04:00
Paolo Bonzini
d495f942f4 KVM: fix bad user ABI for KVM_EXIT_SYSTEM_EVENT
When KVM_EXIT_SYSTEM_EVENT was introduced, it included a flags
member that at the time was unused.  Unfortunately this extensibility
mechanism has several issues:

- x86 is not writing the member, so it would not be possible to use it
  on x86 except for new events

- the member is not aligned to 64 bits, so the definition of the
  uAPI struct is incorrect for 32- on 64-bit userspace.  This is a
  problem for RISC-V, which supports CONFIG_KVM_COMPAT, but fortunately
  usage of flags was only introduced in 5.18.

Since padding has to be introduced, place a new field in there
that tells if the flags field is valid.  To allow further extensibility,
in fact, change flags to an array of 16 values, and store how many
of the values are valid.  The availability of the new ndata field
is tied to a system capability; all architectures are changed to
fill in the field.

To avoid breaking compilation of userspace that was using the flags
field, provide a userspace-only union to overlap flags with data[0].
The new field is placed at the same offset for both 32- and 64-bit
userspace.

Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Peter Gonda <pgonda@google.com>
Cc: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reported-by: kernel test robot <lkp@intel.com>
Message-Id: <20220422103013.34832-1-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-29 12:38:22 -04:00
Sean Christopherson
2031f28768 KVM: Add helpers to wrap vcpu->srcu_idx and yell if it's abused
Add wrappers to acquire/release KVM's SRCU lock when stashing the index
in vcpu->src_idx, along with rudimentary detection of illegal usage,
e.g. re-acquiring SRCU and thus overwriting vcpu->src_idx.  Because the
SRCU index is (currently) either 0 or 1, illegal nesting bugs can go
unnoticed for quite some time and only cause problems when the nested
lock happens to get a different index.

Wrap the WARNs in PROVE_RCU=y, and make them ONCE, otherwise KVM will
likely yell so loudly that it will bring the kernel to its knees.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Tested-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20220415004343.2203171-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-21 13:16:11 -04:00
Sean Christopherson
fdd6f6ac2e KVM: RISC-V: Use kvm_vcpu.srcu_idx, drop RISC-V's unnecessary copy
Use the generic kvm_vcpu's srcu_idx instead of using an indentical field
in RISC-V's version of kvm_vcpu_arch.  Generic KVM very intentionally
does not touch vcpu->srcu_idx, i.e. there's zero chance of running afoul
of common code.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220415004343.2203171-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-21 13:16:10 -04:00
Atish Patra
38d9a4ac65 RISC-V: KVM: Restrict the extensions that can be disabled
Currently, the config isa register allows us to disable all allowed
single letter ISA extensions. It shouldn't be the case as vmm shouldn't
be able to disable base extensions (imac).

These extensions should always be enabled as long as they are enabled
in the host ISA.

Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
Fixes: 92ad82002c ("RISC-V: KVM: Implement
KVM_GET_ONE_REG/KVM_SET_ONE_REG ioctls")
2022-04-20 14:24:32 +05:30
Atish Patra
3ab75a793e RISC-V: KVM: Remove 's' & 'u' as valid ISA extension
There are no ISA extension defined as 's' & 'u' in RISC-V specifications.
The misa register defines 's' & 'u' bit as Supervisor/User privilege mode
enabled. But it should not appear in the ISA extension in the device tree.

Remove those from the allowed ISA extension for kvm.

Fixes: a33c72faf2 ("RISC-V: KVM: Implement VCPU create, init and
destroy functions")
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-04-20 13:42:49 +05:30
Heiko Stuebner
4054eee929 RISC-V: KVM: include missing hwcap.h into vcpu_fp
vcpu_fp uses the riscv_isa_extension mechanism which gets
defined in hwcap.h but doesn't include that head file.

While it seems to work in most cases, in certain conditions
this can lead to build failures like

../arch/riscv/kvm/vcpu_fp.c: In function ‘kvm_riscv_vcpu_fp_reset’:
../arch/riscv/kvm/vcpu_fp.c:22:13: error: implicit declaration of function ‘riscv_isa_extension_available’ [-Werror=implicit-function-declaration]
   22 |         if (riscv_isa_extension_available(&isa, f) ||
      |             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../arch/riscv/kvm/vcpu_fp.c:22:49: error: ‘f’ undeclared (first use in this function)
   22 |         if (riscv_isa_extension_available(&isa, f) ||

Fix this by simply including the necessary header.

Fixes: 0a86512dc1 ("RISC-V: KVM: Factor-out FP virtualization into separate
sources")
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-04-09 09:16:00 +05:30
Anup Patel
8c3ce496bd RISC-V: KVM: Don't clear hgatp CSR in kvm_arch_vcpu_put()
We might have RISC-V systems (such as QEMU) where VMID is not part
of the TLB entry tag so these systems will have to flush all TLB
entries upon any change in hgatp.VMID.

Currently, we zero-out hgatp CSR in kvm_arch_vcpu_put() and we
re-program hgatp CSR in kvm_arch_vcpu_load(). For above described
systems, this will flush all TLB entries whenever VCPU exits to
user-space hence reducing performance.

This patch fixes above described performance issue by not clearing
hgatp CSR in kvm_arch_vcpu_put().

Fixes: 34bde9d8b9 ("RISC-V: KVM: Implement VCPU world-switch")
Cc: stable@vger.kernel.org
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-04-09 09:15:33 +05:30
Anup Patel
763c8bed8c RISC-V: KVM: Implement SBI HSM suspend call
The SBI v0.3 specification extends SBI HSM extension by adding SBI HSM
suspend call and related HART states. This patch extends the KVM RISC-V
HSM implementation to provide KVM guest a minimal SBI HSM suspend call
which is equivalent to a WFI instruction.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-03-11 19:02:39 +05:30
Anup Patel
c9d3b5bd26 RISC-V: KVM: Add common kvm_riscv_vcpu_wfi() function
The wait for interrupt (WFI) instruction emulation can share the VCPU
halt logic with SBI HSM suspend emulation so this patch adds a common
kvm_riscv_vcpu_wfi() function for this purpose.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-03-11 19:02:37 +05:30
Anup Patel
c38ff47bf0 RISC-V: Add SBI HSM suspend related defines
We add defines related to SBI HSM suspend call and also update HSM states
naming as-per the latest SBI specification.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-03-11 19:02:34 +05:30
Anup Patel
be78aa8a38 RISC-V: KVM: Implement SBI v0.3 SRST extension
The SBI v0.3 specification defines SRST (System Reset) extension which
provides a standard poweroff and reboot interface. This patch implements
SRST extension for the KVM Guest.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-03-11 19:02:31 +05:30
Anup Patel
4b11d86571 RISC-V: KVM: Add common kvm_riscv_vcpu_sbi_system_reset() function
We rename kvm_sbi_system_shutdown() to kvm_riscv_vcpu_sbi_system_reset()
and move it to vcpu_sbi.c so that it can be shared by SBI v0.1 shutdown
and SBI v0.3 SRST extension.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-03-11 19:02:29 +05:30
Vincent Chen
823f53a30e RISC-V: KVM: Refine __kvm_riscv_switch_to() implementation
Kernel uses __kvm_riscv_switch_to() and __kvm_switch_return() to switch
the context of host kernel and guest kernel. Several CSRs belonging to the
context will be read and written during the context switch. To ensure
atomic read-modify-write control of CSR and ordering of CSR accesses, some
hardware blocks flush the pipeline when writing a CSR. In this
circumstance, grouping CSR executions together as much as possible can
reduce the performance impact of the pipeline. Therefore, this commit
reorders the CSR instructions to enhance the context switch performance..

Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Suggested-by: Hsinyi Lee <hsinyi.lee@sifive.com>
Suggested-by: Fu-Ching Yang <fu-ching.yang@sifive.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-03-11 19:02:22 +05:30
Yang Li
8eb3e1b923 RISC-V: KVM: remove unneeded semicolon
Eliminate the following coccicheck warning:
./arch/riscv/kvm/vcpu_sbi_v01.c:117:2-3: Unneeded semicolon

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-03-11 19:02:13 +05:30
Paolo Bonzini
7e6a6b400d KVM/arm64 fixes for 5.17, take #2
- A couple of fixes when handling an exception while a SError has been
   delivered
 
 - Workaround for Cortex-A510's single-step[ erratum
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Merge tag 'kvmarm-fixes-5.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 5.17, take #2

- A couple of fixes when handling an exception while a SError has been
  delivered

- Workaround for Cortex-A510's single-step[ erratum
2022-02-05 00:58:25 -05:00
Anup Patel
403271548a RISC-V: KVM: Fix SBI implementation version
The SBI implementation version returned by KVM RISC-V should be the
Host Linux version code.

Fixes: c62a768597 ("RISC-V: KVM: Add SBI v0.2 base extension")
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-02-02 18:58:06 +05:30
Mayuresh Chitale
de1d7b6a51 RISC-V: KVM: make CY, TM, and IR counters accessible in VU mode
Those applications that run in VU mode and access the time CSR cause
a virtual instruction trap as Guest kernel currently does not
initialize the scounteren CSR.

To fix this, we should make CY, TM, and IR counters accessibile
by default in VU mode (similar to OpenSBI).

Fixes: a33c72faf2 ("RISC-V: KVM: Implement VCPU create, init and
destroy functions")
Cc: stable@vger.kernel.org
Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-02-02 18:57:10 +05:30
Mark Rutland
6455317e4d kvm/riscv: rework guest entry logic
In kvm_arch_vcpu_ioctl_run() we enter an RCU extended quiescent state
(EQS) by calling guest_enter_irqoff(), and unmask IRQs prior to exiting
the EQS by calling guest_exit(). As the IRQ entry code will not wake RCU
in this case, we may run the core IRQ code and IRQ handler without RCU
watching, leading to various potential problems.

Additionally, we do not inform lockdep or tracing that interrupts will
be enabled during guest execution, which caan lead to misleading traces
and warnings that interrupts have been enabled for overly-long periods.

This patch fixes these issues by using the new timing and context
entry/exit helpers to ensure that interrupts are handled during guest
vtime but with RCU watching, with a sequence:

	guest_timing_enter_irqoff();

	guest_state_enter_irqoff();
	< run the vcpu >
	guest_state_exit_irqoff();

	< take any pending IRQs >

	guest_timing_exit_irqoff();

Since instrumentation may make use of RCU, we must also ensure that no
instrumented code is run during the EQS. I've split out the critical
section into a new kvm_riscv_enter_exit_vcpu() helper which is marked
noinstr.

Fixes: 99cdc6c18c ("RISC-V: Add initial skeletal KVM support")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Anup Patel <anup@brainfault.org>
Cc: Atish Patra <atishp@atishpatra.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Tested-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Anup Patel <anup@brainfault.org>
2022-02-02 17:45:44 +05:30
Atish Patra
26fb751ca3
RISC-V: Do not use cpumask data structure for hartid bitmap
Currently, SBI APIs accept a hartmask that is generated from struct
cpumask. Cpumask data structure can hold upto NR_CPUs value. Thus, it
is not the correct data structure for hartids as it can be higher
than NR_CPUs for platforms with sparse or discontguous hartids.

Remove all association between hartid mask and struct cpumask.

Reviewed-by: Anup Patel <anup@brainfault.org> (For Linux RISC-V changes)
Acked-by: Anup Patel <anup@brainfault.org> (For KVM RISC-V changes)
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-01-20 09:27:22 -08:00
Vincent Chen
33e5b5746c KVM: RISC-V: Avoid spurious virtual interrupts after clearing hideleg CSR
When the last VM is terminated, the host kernel will invoke function
hardware_disable_nolock() on each CPU to disable the related virtualization
functions. Here, RISC-V currently only clears hideleg CSR and hedeleg CSR.
This behavior will cause the host kernel to receive spurious interrupts if
hvip CSR has pending interrupts and the corresponding enable bits in vsie
CSR are asserted. To avoid it, hvip CSR and vsie CSR must be cleared
before clearing hideleg CSR.

Fixes: 99cdc6c18c ("RISC-V: Add initial skeletal KVM support")
Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
2022-01-06 15:18:18 +05:30
Anup Patel
a457fd5660 RISC-V: KVM: Add VM capability to allow userspace get GPA bits
The number of GPA bits supported for a RISC-V Guest/VM is based on the
MMU mode used by the G-stage translation. The KVM RISC-V will detect and
use the best possible MMU mode for the G-stage in kvm_arch_init().

We add a generic VM capability KVM_CAP_VM_GPA_BITS which can be used by
the KVM userspace to get the number of GPA (guest physical address) bits
supported for a Guest/VM.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-and-tested-by: Atish Patra <atishp@rivosinc.com>
2022-01-06 15:16:58 +05:30
Anup Patel
ef8949a986 RISC-V: KVM: Forward SBI experimental and vendor extensions
The SBI experimental extension space is for temporary (or experimental)
stuff whereas SBI vendor extension space is for hardware vendor specific
stuff. Both these SBI extension spaces won't be standardized by the SBI
specification so let's blindly forward such SBI calls to the userspace.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-and-tested-by: Atish Patra <atishp@rivosinc.com>
2022-01-06 15:14:33 +05:30
Jisheng Zhang
637ad6551b RISC-V: KVM: make kvm_riscv_vcpu_fp_clean() static
There are no users outside vcpu_fp.c so make kvm_riscv_vcpu_fp_clean()
static.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
2022-01-06 15:13:58 +05:30
Atish Patra
3e1d86569c RISC-V: KVM: Add SBI HSM extension in KVM
SBI HSM extension allows OS to start/stop harts any time. It also allows
ordered booting of harts instead of random booting.

Implement SBI HSM exntesion and designate the vcpu 0 as the boot vcpu id.
All other non-zero non-booting vcpus should be brought up by the OS
implementing HSM extension. If the guest OS doesn't implement HSM
extension, only single vcpu will be available to OS.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
2022-01-06 15:12:47 +05:30
Atish Patra
5f862df558 RISC-V: KVM: Add v0.1 replacement SBI extensions defined in v0.2
The SBI v0.2 contains some of the improved versions of required v0.1
extensions such as remote fence, timer and IPI.

This patch implements those extensions.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
2022-01-06 15:12:15 +05:30
Atish Patra
c62a768597 RISC-V: KVM: Add SBI v0.2 base extension
SBI v0.2 base extension defined to allow backward compatibility and
probing of future extensions. This is also the only mandatory SBI
extension that must be implemented by SBI implementors.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
2022-01-06 15:08:29 +05:30
Atish Patra
a046c2d857 RISC-V: KVM: Reorganize SBI code by moving SBI v0.1 to its own file
With SBI v0.2, there may be more SBI extensions in future. It makes more
sense to group related extensions in separate files. Guest kernel will
choose appropriate SBI version dynamically.

Move the existing implementation to a separate file so that it can be
removed in future without much conflict.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
2022-01-06 14:57:16 +05:30
Atish Patra
cf70be9d21 RISC-V: KVM: Mark the existing SBI implementation as v0.1
The existing SBI specification impelementation follows v0.1
specification. The latest specification allows more scalability
and performance improvements.

Rename the existing implementation as v0.1 and provide a way
to allow future extensions.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
2022-01-06 14:38:52 +05:30
Sean Christopherson
cc4f602bc4 KVM: RISC-V: Use common KVM implementation of MMU memory caches
Use common KVM's implementation of the MMU memory caches, which for all
intents and purposes is semantically identical to RISC-V's version, the
only difference being that the common implementation will fall back to an
atomic allocation if there's a KVM bug that triggers a cache underflow.

RISC-V appears to have based its MMU code on arm64 before the conversion
to the common caches in commit c1a33aebe9 ("KVM: arm64: Use common KVM
implementation of MMU memory caches"), despite having also copy-pasted
the definition of KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE in kvm_types.h.

Opportunistically drop the superfluous wrapper
kvm_riscv_stage2_flush_cache(), whose name is very, very confusing as
"cache flush" in the context of MMU code almost always refers to flushing
hardware caches, not freeing unused software objects.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
2022-01-06 14:38:50 +05:30
David Woodhouse
3e3aa26fd4 KVM: RISC-V: Use Makefile.kvm for common files
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20211121125451.9489-6-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-09 12:59:08 -05:00
Sean Christopherson
91b99ea706 KVM: Rename kvm_vcpu_block() => kvm_vcpu_halt()
Rename kvm_vcpu_block() to kvm_vcpu_halt() in preparation for splitting
the actual "block" sequences into a separate helper (to be named
kvm_vcpu_block()).  x86 will use the standalone block-only path to handle
non-halt cases where the vCPU is not runnable.

Rename block_ns to halt_ns to match the new function name.

No functional change intended.

Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211009021236.4122790-14-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08 04:24:51 -05:00
Sean Christopherson
6a99c6e3f5 KVM: Stop passing kvm_userspace_memory_region to arch memslot hooks
Drop the @mem param from kvm_arch_{prepare,commit}_memory_region() now
that its use has been removed in all architectures.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <aa5ed3e62c27e881d0d8bc0acbc1572bc336dc19.1638817640.git.maciej.szmigiero@oracle.com>
2021-12-08 04:24:25 -05:00
Sean Christopherson
d01495d4cf KVM: RISC-V: Use "new" memslot instead of userspace memory region
Get the slot ID, hva, etc... from the "new" memslot instead of the
userspace memory region when preparing/committing a memory region.  This
will allow a future commit to drop @mem from the prepare/commit hooks
once all architectures convert to using "new".

Opportunistically wait to get the various "new" values until after
filtering out the DELETE case in anticipation of a future commit passing
NULL for @new when deleting a memslot.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <543608ab88a1190e73a958efffafc98d2652c067.1638817640.git.maciej.szmigiero@oracle.com>
2021-12-08 04:24:24 -05:00
Sean Christopherson
537a17b314 KVM: Let/force architectures to deal with arch specific memslot data
Pass the "old" slot to kvm_arch_prepare_memory_region() and force arch
code to handle propagating arch specific data from "new" to "old" when
necessary.  This is a baby step towards dynamically allocating "new" from
the get go, and is a (very) minor performance boost on x86 due to not
unnecessarily copying arch data.

For PPC HV, copy the rmap in the !CREATE and !DELETE paths, i.e. for MOVE
and FLAGS_ONLY.  This is functionally a nop as the previous behavior
would overwrite the pointer for CREATE, and eventually discard/ignore it
for DELETE.

For x86, copy the arch data only for FLAGS_ONLY changes.  Unlike PPC HV,
x86 needs to reallocate arch data in the MOVE case as the size of x86's
allocations depend on the alignment of the memslot's gfn.

Opportunistically tweak kvm_arch_prepare_memory_region()'s param order to
match the "commit" prototype.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
[mss: add missing RISCV kvm_arch_prepare_memory_region() change]
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <67dea5f11bbcfd71e3da5986f11e87f5dd4013f9.1638817639.git.maciej.szmigiero@oracle.com>
2021-12-08 04:24:20 -05:00
Marc Zyngier
46808a4cb8 KVM: Use 'unsigned long' as kvm_for_each_vcpu()'s index
Everywhere we use kvm_for_each_vpcu(), we use an int as the vcpu
index. Unfortunately, we're about to move rework the iterator,
which requires this to be upgrade to an unsigned long.

Let's bite the bullet and repaint all of it in one go.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Message-Id: <20211116160403.4074052-7-maz@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08 04:24:15 -05:00
Marc Zyngier
27592ae8db KVM: Move wiping of the kvm->vcpus array to common code
All architectures have similar loops iterating over the vcpus,
freeing one vcpu at a time, and eventually wiping the reference
off the vcpus array. They are also inconsistently taking
the kvm->lock mutex when wiping the references from the array.

Make this code common, which will simplify further changes.
The locking is dropped altogether, as this should only be called
when there is no further references on the kvm structure.

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Message-Id: <20211116160403.4074052-2-maz@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08 04:24:13 -05:00
Sean Christopherson
756e1fc165 KVM: RISC-V: Unmap stage2 mapping when deleting/moving a memslot
Unmap stage2 page tables when a memslot is being deleted or moved.  It's
the architectures' responsibility to ensure existing mappings are removed
when kvm_arch_flush_shadow_memslot() returns.

Fixes: 9d05c1fee8 ("RISC-V: KVM: Implement stage2 page table programming")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
2021-11-22 10:36:16 +05:30
Linus Torvalds
c46e8ece96 Selftest changes:
* Cleanups for the perf test infrastructure and mapping hugepages
 
 * Avoid contention on mmap_sem when the guests start to run
 
 * Add event channel upcall support to xen_shinfo_test
 
 x86 changes:
 
 * Fixes for Xen emulation
 
 * Kill kvm_map_gfn() / kvm_unmap_gfn() and broken gfn_to_pfn_cache
 
 * Fixes for migration of 32-bit nested guests on 64-bit hypervisor
 
 * Compilation fixes
 
 * More SEV cleanups
 
 Generic:
 
 * Cap the return value of KVM_CAP_NR_VCPUS to both KVM_CAP_MAX_VCPUS
 and num_online_cpus().  Most architectures were only using one of the two.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fixes from Paolo Bonzini:
 "Selftest changes:

   - Cleanups for the perf test infrastructure and mapping hugepages

   - Avoid contention on mmap_sem when the guests start to run

   - Add event channel upcall support to xen_shinfo_test

  x86 changes:

   - Fixes for Xen emulation

   - Kill kvm_map_gfn() / kvm_unmap_gfn() and broken gfn_to_pfn_cache

   - Fixes for migration of 32-bit nested guests on 64-bit hypervisor

   - Compilation fixes

   - More SEV cleanups

  Generic:

   - Cap the return value of KVM_CAP_NR_VCPUS to both KVM_CAP_MAX_VCPUS
     and num_online_cpus(). Most architectures were only using one of
     the two"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (42 commits)
  KVM: x86: Cap KVM_CAP_NR_VCPUS by KVM_CAP_MAX_VCPUS
  KVM: s390: Cap KVM_CAP_NR_VCPUS by num_online_cpus()
  KVM: RISC-V: Cap KVM_CAP_NR_VCPUS by KVM_CAP_MAX_VCPUS
  KVM: PPC: Cap KVM_CAP_NR_VCPUS by KVM_CAP_MAX_VCPUS
  KVM: MIPS: Cap KVM_CAP_NR_VCPUS by KVM_CAP_MAX_VCPUS
  KVM: arm64: Cap KVM_CAP_NR_VCPUS by kvm_arm_default_max_vcpus()
  KVM: x86: Assume a 64-bit hypercall for guests with protected state
  selftests: KVM: Add /x86_64/sev_migrate_tests to .gitignore
  riscv: kvm: fix non-kernel-doc comment block
  KVM: SEV: Fix typo in and tweak name of cmd_allowed_from_miror()
  KVM: SEV: Drop a redundant setting of sev->asid during initialization
  KVM: SEV: WARN if SEV-ES is marked active but SEV is not
  KVM: SEV: Set sev_info.active after initial checks in sev_guest_init()
  KVM: SEV: Disallow COPY_ENC_CONTEXT_FROM if target has created vCPUs
  KVM: Kill kvm_map_gfn() / kvm_unmap_gfn() and gfn_to_pfn_cache
  KVM: nVMX: Use a gfn_to_hva_cache for vmptrld
  KVM: nVMX: Use kvm_read_guest_offset_cached() for nested VMCS check
  KVM: x86/xen: Use sizeof_field() instead of open-coding it
  KVM: nVMX: Use kvm_{read,write}_guest_cached() for shadow_vmcs12
  KVM: x86/xen: Fix get_attr of KVM_XEN_ATTR_TYPE_SHARED_INFO
  ...
2021-11-18 12:05:22 -08:00
Vitaly Kuznetsov
37fd3ce1e6 KVM: RISC-V: Cap KVM_CAP_NR_VCPUS by KVM_CAP_MAX_VCPUS
It doesn't make sense to return the recommended maximum number of
vCPUs which exceeds the maximum possible number of vCPUs.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Message-Id: <20211116163443.88707-5-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:12:14 -05:00
Randy Dunlap
0e2e641921 riscv: kvm: fix non-kernel-doc comment block
Don't use "/**" to begin a comment block for a non-kernel-doc comment.

Prevents this docs build warning:

vcpu_sbi.c:3: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
 * Copyright (c) 2019 Western Digital Corporation or its affiliates.

Fixes: dea8ee31a0 ("RISC-V: KVM: Add SBI v0.1 support")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Atish Patra <atish.patra@wdc.com>
Cc: Anup Patel <anup.patel@wdc.com>
Cc: kvm@vger.kernel.org
Cc: kvm-riscv@lists.infradead.org
Cc: linux-riscv@lists.infradead.org
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Message-Id: <20211107034706.30672-1-rdunlap@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-18 02:12:13 -05:00
Mauro Carvalho Chehab
636e36b19d Documentation: update vcpu-requests.rst reference
Changeset 2f5947dfca ("Documentation: move Documentation/virtual to Documentation/virt")
renamed: Documentation/virtual/kvm/vcpu-requests.rst
to: Documentation/virt/kvm/vcpu-requests.rst.

Update its cross-reference accordingly.

Fixes: 2f5947dfca ("Documentation: move Documentation/virtual to Documentation/virt")
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-11-17 06:12:14 -07:00
Bixuan Cui
bbd5ba8db7 RISC-V: KVM: fix boolreturn.cocci warnings
Fix boolreturn.cocci warnings:
./arch/riscv/kvm/mmu.c:603:9-10: WARNING: return of 0/1 in function
'kvm_age_gfn' with return type bool
./arch/riscv/kvm/mmu.c:582:9-10: WARNING: return of 0/1 in function
'kvm_set_spte_gfn' with return type bool
./arch/riscv/kvm/mmu.c:621:9-10: WARNING: return of 0/1 in function
'kvm_test_age_gfn' with return type bool
./arch/riscv/kvm/mmu.c:568:9-10: WARNING: return of 0/1 in function
'kvm_unmap_gfn_range' with return type bool

Signed-off-by: Bixuan Cui <cuibixuan@linux.alibaba.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
2021-11-01 17:35:17 +05:30