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| author | Marc Zyngier | 2016-10-18 19:37:49 +0200 |
|---|---|---|
| committer | Marc Zyngier | 2016-11-04 18:56:28 +0100 |
| commit | 94d0e5980d6791b9f98a9b6c586c1f7cb76b2178 (patch) | |
| tree | f513c7147798d74dee9b3f1a79dd0ded62d9aa37 /arch/arm/include/asm | |
| parent | Linux 4.9-rc2 (diff) | |
| download | kernel-qcow2-linux-94d0e5980d6791b9f98a9b6c586c1f7cb76b2178.tar.gz kernel-qcow2-linux-94d0e5980d6791b9f98a9b6c586c1f7cb76b2178.tar.xz kernel-qcow2-linux-94d0e5980d6791b9f98a9b6c586c1f7cb76b2178.zip | |
arm/arm64: KVM: Perform local TLB invalidation when multiplexing vcpus on a single CPU
Architecturally, TLBs are private to the (physical) CPU they're
associated with. But when multiple vcpus from the same VM are
being multiplexed on the same CPU, the TLBs are not private
to the vcpus (and are actually shared across the VMID).
Let's consider the following scenario:
- vcpu-0 maps PA to VA
- vcpu-1 maps PA' to VA
If run on the same physical CPU, vcpu-1 can hit TLB entries generated
by vcpu-0 accesses, and access the wrong physical page.
The solution to this is to keep a per-VM map of which vcpu ran last
on each given physical CPU, and invalidate local TLBs when switching
to a different vcpu from the same VM.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch/arm/include/asm')
| -rw-r--r-- | arch/arm/include/asm/kvm_asm.h | 1 | ||||
| -rw-r--r-- | arch/arm/include/asm/kvm_host.h | 3 | ||||
| -rw-r--r-- | arch/arm/include/asm/kvm_hyp.h | 1 |
3 files changed, 5 insertions, 0 deletions
diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h index d7ea6bcb29bf..8ef05381984b 100644 --- a/arch/arm/include/asm/kvm_asm.h +++ b/arch/arm/include/asm/kvm_asm.h @@ -66,6 +66,7 @@ extern char __kvm_hyp_vector[]; extern void __kvm_flush_vm_context(void); extern void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa); extern void __kvm_tlb_flush_vmid(struct kvm *kvm); +extern void __kvm_tlb_flush_local_vmid(struct kvm_vcpu *vcpu); extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu); diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 2d19e02d03fd..d5423ab15ed5 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -57,6 +57,9 @@ struct kvm_arch { /* VTTBR value associated with below pgd and vmid */ u64 vttbr; + /* The last vcpu id that ran on each physical CPU */ + int __percpu *last_vcpu_ran; + /* Timer */ struct arch_timer_kvm timer; diff --git a/arch/arm/include/asm/kvm_hyp.h b/arch/arm/include/asm/kvm_hyp.h index 343135ede5fa..58508900c4bb 100644 --- a/arch/arm/include/asm/kvm_hyp.h +++ b/arch/arm/include/asm/kvm_hyp.h @@ -71,6 +71,7 @@ #define ICIALLUIS __ACCESS_CP15(c7, 0, c1, 0) #define ATS1CPR __ACCESS_CP15(c7, 0, c8, 0) #define TLBIALLIS __ACCESS_CP15(c8, 0, c3, 0) +#define TLBIALL __ACCESS_CP15(c8, 0, c7, 0) #define TLBIALLNSNHIS __ACCESS_CP15(c8, 4, c3, 4) #define PRRR __ACCESS_CP15(c10, 0, c2, 0) #define NMRR __ACCESS_CP15(c10, 0, c2, 1) |