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| author | Marc Zyngier <maz@kernel.org> | 2023-04-26 20:23:30 +0300 |
|---|---|---|
| committer | Oliver Upton <oliver.upton@linux.dev> | 2023-05-16 20:39:19 +0300 |
| commit | a12ab1378a88b38f3af8b1a899b7d8526324ba6f (patch) | |
| tree | 67c2fefbd6c0014b4ad71496b341fb11585183bf /arch/arm64/include/asm/kvm_asm.h | |
| parent | 6acf51666d039857421b6f8a3660301c82649fa5 (diff) | |
| download | linux-a12ab1378a88b38f3af8b1a899b7d8526324ba6f.tar.xz | |
KVM: arm64: Use local TLBI on permission relaxation
Broadcast TLB invalidations (TLBIs) targeting the Inner Shareable
Domain are usually less performant than their non-shareable variant.
In particular, we observed some implementations that take
millliseconds to complete parallel broadcasted TLBIs.
It's safe to use non-shareable TLBIs when relaxing permissions on a
PTE in the KVM case. According to the ARM ARM (0487I.a) section
D8.13.1 "Using break-before-make when updating translation table
entries", permission relaxation does not need break-before-make.
Specifically, R_WHZWS states that these are the only changes that
require a break-before-make sequence: changes of memory type
(Shareability or Cacheability), address changes, or changing the block
size.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Link: https://lore.kernel.org/r/20230426172330.1439644-13-ricarkol@google.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Diffstat (limited to 'arch/arm64/include/asm/kvm_asm.h')
| -rw-r--r-- | arch/arm64/include/asm/kvm_asm.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index 43c3bc0f9544..bb17b2ead4c7 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -68,6 +68,7 @@ enum __kvm_host_smccc_func { __KVM_HOST_SMCCC_FUNC___kvm_vcpu_run, __KVM_HOST_SMCCC_FUNC___kvm_flush_vm_context, __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa, + __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa_nsh, __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid, __KVM_HOST_SMCCC_FUNC___kvm_flush_cpu_context, __KVM_HOST_SMCCC_FUNC___kvm_timer_set_cntvoff, @@ -225,6 +226,9 @@ extern void __kvm_flush_vm_context(void); extern void __kvm_flush_cpu_context(struct kvm_s2_mmu *mmu); extern void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t ipa, int level); +extern void __kvm_tlb_flush_vmid_ipa_nsh(struct kvm_s2_mmu *mmu, + phys_addr_t ipa, + int level); extern void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu); extern void __kvm_timer_set_cntvoff(u64 cntvoff); |