From adc43caa0a25746e1a9dabbab241abd01120dbfe Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Tue, 1 Nov 2022 15:53:46 +0100 Subject: [PATCH] KVM: x86: hyper-v: Resurrect dedicated KVM_REQ_HV_TLB_FLUSH flag In preparation to implementing fine-grained Hyper-V TLB flush and L2 TLB flush, resurrect dedicated KVM_REQ_HV_TLB_FLUSH request bit. As KVM_REQ_TLB_FLUSH_GUEST is a stronger operation, clear KVM_REQ_HV_TLB_FLUSH request in kvm_vcpu_flush_tlb_guest(). The flush itself is temporary handled by kvm_vcpu_flush_tlb_guest(). No functional change intended. Reviewed-by: Sean Christopherson Signed-off-by: Vitaly Kuznetsov Signed-off-by: Paolo Bonzini Message-Id: <20221101145426.251680-9-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/kvm_host.h | 2 ++ arch/x86/kvm/hyperv.c | 4 ++-- arch/x86/kvm/svm/svm.c | 7 +++++++ arch/x86/kvm/x86.c | 9 +++++++++ 4 files changed, 20 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index a413f841e830..0b85230a0e0a 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -110,6 +110,8 @@ KVM_ARCH_REQ_FLAGS(30, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP) #define KVM_REQ_MMU_FREE_OBSOLETE_ROOTS \ KVM_ARCH_REQ_FLAGS(31, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP) +#define KVM_REQ_HV_TLB_FLUSH \ + KVM_ARCH_REQ_FLAGS(32, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP) #define CR0_RESERVED_BITS \ (~(unsigned long)(X86_CR0_PE | X86_CR0_MP | X86_CR0_EM | X86_CR0_TS \ diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 0adf4a437e85..3c0f639f6a05 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -1870,11 +1870,11 @@ do_flush: * analyze it here, flush TLB regardless of the specified address space. */ if (all_cpus) { - kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH_GUEST); + kvm_make_all_cpus_request(kvm, KVM_REQ_HV_TLB_FLUSH); } else { sparse_set_to_vcpu_mask(kvm, sparse_banks, valid_bank_mask, vcpu_mask); - kvm_make_vcpus_request_mask(kvm, KVM_REQ_TLB_FLUSH_GUEST, vcpu_mask); + kvm_make_vcpus_request_mask(kvm, KVM_REQ_HV_TLB_FLUSH, vcpu_mask); } ret_success: diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 7efc4fdaa446..4ea6ddd99899 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -3723,6 +3723,13 @@ static void svm_flush_tlb_current(struct kvm_vcpu *vcpu) struct vcpu_svm *svm = to_svm(vcpu); /* + * Unlike VMX, SVM doesn't provide a way to flush only NPT TLB entries. + * A TLB flush for the current ASID flushes both "host" and "guest" TLB + * entries, and thus is a superset of Hyper-V's fine grained flushing. + */ + kvm_clear_request(KVM_REQ_HV_TLB_FLUSH, vcpu); + + /* * Flush only the current ASID even if the TLB flush was invoked via * kvm_flush_remote_tlbs(). Although flushing remote TLBs requires all * ASIDs to be flushed, KVM uses a single ASID for L1 and L2, and diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 7fc5508c0b4a..12e49e8566d4 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3420,6 +3420,12 @@ static void kvm_vcpu_flush_tlb_guest(struct kvm_vcpu *vcpu) } static_call(kvm_x86_flush_tlb_guest)(vcpu); + + /* + * Flushing all "guest" TLB is always a superset of Hyper-V's fine + * grained flushing. + */ + kvm_clear_request(KVM_REQ_HV_TLB_FLUSH, vcpu); } @@ -10250,6 +10256,9 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) kvm_service_local_tlb_flush_requests(vcpu); + if (kvm_check_request(KVM_REQ_HV_TLB_FLUSH, vcpu)) + kvm_vcpu_flush_tlb_guest(vcpu); + if (kvm_check_request(KVM_REQ_REPORT_TPR_ACCESS, vcpu)) { vcpu->run->exit_reason = KVM_EXIT_TPR_ACCESS; r = 0; -- 2.11.0