From 05a518b49dd6f674cd0b1fe1eb6c8f9c3953b63d Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 27 Nov 2024 16:43:42 -0800 Subject: [PATCH] KVM: x86: Bump hypercall stat prior to fully completing hypercall Increment the "hypercalls" stat for KVM hypercalls as soon as KVM knows it will skip the guest instruction, i.e. once KVM is committed to emulating the hypercall. Waiting until completion adds no known value, and creates a discrepancy where the stat will be bumped if KVM exits to userspace as a result of trying to skip the instruction, but not if the hypercall itself exits. Handling the stat in common code will also avoid the need for another helper to dedup code when TDX comes along (TDX needs a separate completion path due to GPR usage differences). Signed-off-by: Sean Christopherson Reviewed-by: Binbin Wu Reviewed-by: Kai Huang Reviewed-by: Tom Lendacky Reviewed-by: Xiaoyao Li Message-ID: <20241128004344.4072099-5-seanjc@google.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/x86.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index d485a53ac4103..754d8166eabfa 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9979,7 +9979,6 @@ static int complete_hypercall_exit(struct kvm_vcpu *vcpu) if (!is_64_bit_hypercall(vcpu)) ret = (u32)ret; kvm_rax_write(vcpu, ret); - ++vcpu->stat.hypercalls; return kvm_skip_emulated_instruction(vcpu); } @@ -9990,6 +9989,8 @@ unsigned long __kvm_emulate_hypercall(struct kvm_vcpu *vcpu, unsigned long nr, { unsigned long ret; + ++vcpu->stat.hypercalls; + trace_kvm_hypercall(nr, a0, a1, a2, a3); if (!op_64_bit) { @@ -10068,7 +10069,6 @@ unsigned long __kvm_emulate_hypercall(struct kvm_vcpu *vcpu, unsigned long nr, WARN_ON_ONCE(vcpu->run->hypercall.flags & KVM_EXIT_HYPERCALL_MBZ); vcpu->arch.complete_userspace_io = complete_hypercall_exit; - /* stat is incremented on completion. */ return 0; } default: @@ -10077,7 +10077,6 @@ unsigned long __kvm_emulate_hypercall(struct kvm_vcpu *vcpu, unsigned long nr, } out: - ++vcpu->stat.hypercalls; return ret; } EXPORT_SYMBOL_GPL(__kvm_emulate_hypercall); -- 2.47.2