From: Liran Alon Date: Wed, 20 Nov 2019 22:31:47 +0000 (+0200) Subject: KVM: nVMX: Do not mark vmcs02->apic_access_page as dirty when unpinning X-Git-Tag: for-5.5/io_uring-post-20191128~43^2~9 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=b11494bcabba7383c9db65132f6f73d64fb1407d;p=linux-block.git KVM: nVMX: Do not mark vmcs02->apic_access_page as dirty when unpinning vmcs->apic_access_page is simply a token that the hypervisor puts into the PFN of a 4KB EPTE (or PTE if using shadow-paging) that triggers APIC-access VMExit or APIC virtualization logic whenever a CPU running in VMX non-root mode read/write from/to this PFN. As every write either triggers an APIC-access VMExit or write is performed on vmcs->virtual_apic_page, the PFN pointed to by vmcs->apic_access_page should never actually be touched by CPU. Therefore, there is no need to mark vmcs02->apic_access_page as dirty after unpin it on L2->L1 emulated VMExit or when L1 exit VMX operation. Reviewed-by: Krish Sadhukhan Reviewed-by: Joao Martins Reviewed-by: Jim Mattson Signed-off-by: Liran Alon Signed-off-by: Paolo Bonzini --- diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 5fb59bed344e..783de6d83f9a 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -268,7 +268,7 @@ static void free_nested(struct kvm_vcpu *vcpu) vmx->nested.cached_shadow_vmcs12 = NULL; /* Unpin physical memory we referred to in the vmcs02 */ if (vmx->nested.apic_access_page) { - kvm_release_page_dirty(vmx->nested.apic_access_page); + kvm_release_page_clean(vmx->nested.apic_access_page); vmx->nested.apic_access_page = NULL; } kvm_vcpu_unmap(vcpu, &vmx->nested.virtual_apic_map, true); @@ -3070,7 +3070,7 @@ static bool nested_get_vmcs12_pages(struct kvm_vcpu *vcpu) * to it so we can release it later. */ if (vmx->nested.apic_access_page) { /* shouldn't happen */ - kvm_release_page_dirty(vmx->nested.apic_access_page); + kvm_release_page_clean(vmx->nested.apic_access_page); vmx->nested.apic_access_page = NULL; } page = kvm_vcpu_gpa_to_page(vcpu, vmcs12->apic_access_addr); @@ -4267,7 +4267,7 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason, /* Unpin physical memory we referred to in vmcs02 */ if (vmx->nested.apic_access_page) { - kvm_release_page_dirty(vmx->nested.apic_access_page); + kvm_release_page_clean(vmx->nested.apic_access_page); vmx->nested.apic_access_page = NULL; } kvm_vcpu_unmap(vcpu, &vmx->nested.virtual_apic_map, true);