Messages in this thread | | | Date | Fri, 15 Oct 2021 18:02:11 +0200 | Subject | Re: [PATCH 0/2] KVM: X86: Don't reset mmu context when changing PGE or PCID | From | Paolo Bonzini <> |
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On 14/10/21 18:03, Lai Jiangshan wrote: > Ping > > On 2021/9/19 10:42, Lai Jiangshan wrote: >> From: Lai Jiangshan <laijs@linux.alibaba.com> >> >> This patchset uses kvm_vcpu_flush_tlb_guest() instead of >> kvm_mmu_reset_context() >> when X86_CR4_PGE is changed or X86_CR4_PCIDE is changed 1->0. >> >> Neither X86_CR4_PGE nor X86_CR4_PCIDE participates in kvm_mmu_role, so >> kvm_mmu_reset_context() is not required to be invoked. Only flushing tlb >> is required as SDM says. >> >> The patchset has nothing to do with performance, because the overheads of >> kvm_mmu_reset_context() and kvm_vcpu_flush_tlb_guest() are the same. And >> even in the [near] future, kvm_vcpu_flush_tlb_guest() will be optimized, >> the code is not in the hot path. >> >> This patchset makes the code more clear when to reset the mmu context. >> And it makes KVM_MMU_CR4_ROLE_BITS consistent with kvm_mmu_role. >> >> Lai Jiangshan (2): >> KVM: X86: Don't reset mmu context when X86_CR4_PCIDE 1->0 >> KVM: X86: Don't reset mmu context when toggling X86_CR4_PGE >> >> arch/x86/kvm/mmu.h | 5 ++--- >> arch/x86/kvm/x86.c | 7 +++++-- >> 2 files changed, 7 insertions(+), 5 deletions(-) >> >
Queued with kvm_make_request(KVM_REQ_TLB_FLUSH_GUEST, vcpu) replacement, thanks.
Paolo
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