| Message ID | 20230621175002.2832640-11-rananta@google.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | KVM: arm64: Add support for FEAT_TLBIRANGE | expand |
| Context | Check | Description |
|---|---|---|
| conchuod/cover_letter | success | Series has a cover letter |
| conchuod/tree_selection | success | Guessed tree name to be for-next at HEAD 4681dacadeef |
| conchuod/fixes_present | success | Fixes tag not required for -next series |
| conchuod/maintainers_pattern | success | MAINTAINERS pattern errors before the patch: 6 and now 6 |
| conchuod/verify_signedoff | success | Signed-off-by tag matches author and committer |
| conchuod/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| conchuod/build_rv64_clang_allmodconfig | success | Errors and warnings before: 8 this patch: 8 |
| conchuod/module_param | success | Was 0 now: 0 |
| conchuod/build_rv64_gcc_allmodconfig | success | Errors and warnings before: 8 this patch: 8 |
| conchuod/build_rv32_defconfig | success | Build OK |
| conchuod/dtb_warn_rv64 | success | Errors and warnings before: 20 this patch: 20 |
| conchuod/header_inline | success | No static functions without inline keyword in header files |
| conchuod/checkpatch | warning | CHECK: Alignment should match open parenthesis |
| conchuod/build_rv64_nommu_k210_defconfig | success | Build OK |
| conchuod/verify_fixes | success | No Fixes tag |
| conchuod/build_rv64_nommu_virt_defconfig | success | Build OK |
On 6/22/23 03:50, Raghavendra Rao Ananta wrote: > Currently, during the operations such as a hugepage collapse, > KVM would flush the entire VM's context using 'vmalls12e1is' > TLBI operation. Specifically, if the VM is faulting on many > hugepages (say after dirty-logging), it creates a performance > penalty for the guest whose pages have already been faulted > earlier as they would have to refill their TLBs again. > > Instead, leverage kvm_tlb_flush_vmid_range() for table entries. > If the system supports it, only the required range will be > flushed. Else, it'll fallback to the previous mechanism. > > Signed-off-by: Raghavendra Rao Ananta <rananta@google.com> > --- > arch/arm64/kvm/hyp/pgtable.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > Reviewed-by: Gavin Shan <gshan@redhat.com> > diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c > index df8ac14d9d3d4..50ef7623c54db 100644 > --- a/arch/arm64/kvm/hyp/pgtable.c > +++ b/arch/arm64/kvm/hyp/pgtable.c > @@ -766,7 +766,8 @@ static bool stage2_try_break_pte(const struct kvm_pgtable_visit_ctx *ctx, > * value (if any). > */ > if (kvm_pte_table(ctx->old, ctx->level)) > - kvm_call_hyp(__kvm_tlb_flush_vmid, mmu); > + kvm_tlb_flush_vmid_range(mmu, ctx->addr, > + kvm_granule_size(ctx->level)); > else if (kvm_pte_valid(ctx->old)) > kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, mmu, ctx->addr, ctx->level); >
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index df8ac14d9d3d4..50ef7623c54db 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -766,7 +766,8 @@ static bool stage2_try_break_pte(const struct kvm_pgtable_visit_ctx *ctx, * value (if any). */ if (kvm_pte_table(ctx->old, ctx->level)) - kvm_call_hyp(__kvm_tlb_flush_vmid, mmu); + kvm_tlb_flush_vmid_range(mmu, ctx->addr, + kvm_granule_size(ctx->level)); else if (kvm_pte_valid(ctx->old)) kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, mmu, ctx->addr, ctx->level);
Currently, during the operations such as a hugepage collapse, KVM would flush the entire VM's context using 'vmalls12e1is' TLBI operation. Specifically, if the VM is faulting on many hugepages (say after dirty-logging), it creates a performance penalty for the guest whose pages have already been faulted earlier as they would have to refill their TLBs again. Instead, leverage kvm_tlb_flush_vmid_range() for table entries. If the system supports it, only the required range will be flushed. Else, it'll fallback to the previous mechanism. Signed-off-by: Raghavendra Rao Ananta <rananta@google.com> --- arch/arm64/kvm/hyp/pgtable.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)