Date:   Mon,  1 Jun 2020 15:24:15 -0700
In-Reply-To: <20200601222416.71303-1-jmattson@google.com>
Message-Id: <20200601222416.71303-4-jmattson@google.com>
Mime-Version: 1.0
References: <20200601222416.71303-1-jmattson@google.com>
Subject: [PATCH v3 3/4] kvm: vmx: Add last_cpu to struct vcpu_vmx
From:   Jim Mattson <jmattson@google.com>
To:     kvm@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>
Cc:     Liran Alon <liran.alon@oracle.com>,
        Oliver Upton <oupton@google.com>,
        Peter Shier <pshier@google.com>,
        Jim Mattson <jmattson@google.com>
Content-Type: text/plain; charset="UTF-8"
Sender: kvm-owner@vger.kernel.org
Precedence: bulk

As we already do in svm, record the last logical processor on which a
vCPU has run, so that it can be communicated to userspace for
potential hardware errors.

Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Reviewed-by: Peter Shier <pshier@google.com>
---
 arch/x86/kvm/vmx/vmx.c | 1 +
 arch/x86/kvm/vmx/vmx.h | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 170cc76a581f..42856970d3b8 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6730,6 +6730,7 @@ static fastpath_t vmx_vcpu_run(struct kvm_vcpu *vcpu)
 	if (vcpu->arch.cr2 != read_cr2())
 		write_cr2(vcpu->arch.cr2);
 
+	vmx->last_cpu = vcpu->cpu;
 	vmx->fail = __vmx_vcpu_run(vmx, (unsigned long *)&vcpu->arch.regs,
 				   vmx->loaded_vmcs->launched);
 
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 672c28f17e49..8a1e833cf4fb 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -302,6 +302,9 @@ struct vcpu_vmx {
 	u64 ept_pointer;
 
 	struct pt_desc pt_desc;
+
+	/* which host CPU was used for running this vcpu */
+	unsigned int last_cpu;
 };
 
 enum ept_pointers_status {
-- 
2.27.0.rc2.251.g90737beb825-goog