On 14/10/21 18:03, Lai Jiangshan wrote:
Ping
On 2021/9/19 10:42, Lai Jiangshan wrote:
From: Lai Jiangshan <laijs@xxxxxxxxxxxxxxxxx>
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
