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[RFC,v3,17/59] KVM: x86: Add flag to disallow #MC injection / KVM_X86_SETUP_MCE

Message ID b7c89ebf9f2000c1f8c3d0e57bd7cf622f11f638.1637799475.git.isaku.yamahata@intel.com (mailing list archive)
State New, archived
Headers show
Series KVM: X86: TDX support | expand

Commit Message

Isaku Yamahata Nov. 25, 2021, 12:20 a.m. UTC 
From: Sean Christopherson <sean.j.christopherson@intel.com>

Add a flag to disallow MCE injection and reject KVM_X86_SETUP_MCE with
-EINVAL when set.  TDX doesn't support injecting exceptions, including
(virtual) #MCs.

Co-developed-by: Kai Huang <kai.huang@linux.intel.com>
Signed-off-by: Kai Huang <kai.huang@linux.intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
 arch/x86/include/asm/kvm_host.h |  1 +
 arch/x86/kvm/x86.c              | 14 +++++++-------
 2 files changed, 8 insertions(+), 7 deletions(-)

Comments

Thomas Gleixner Nov. 25, 2021, 7:33 p.m. UTC | #1 
On Wed, Nov 24 2021 at 16:20, isaku yamahata wrote:
>  static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu *vcpu,
>  					u64 mcg_cap)
>  {
> -	int r;
>  	unsigned bank_num = mcg_cap & 0xff, bank;
>  
> -	r = -EINVAL;
> +	if (vcpu->kvm->arch.mce_injection_disallowed)
> +		return -EINVAL;

Yet another flag because the copy & pasta orgy did not cover that
ioctl. What for?
diff mbox series

Patch

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index ebc4de32bf0e..e912e1e853ef 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1142,6 +1142,7 @@  struct kvm_arch {
 
 	bool bus_lock_detection_enabled;
 	bool irq_injection_disallowed;
+	bool mce_injection_disallowed;
 	/*
 	 * If exit_on_emulation_error is set, and the in-kernel instruction
 	 * emulator fails to emulate an instruction, allow userspace
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b399e64e8863..fefa4602e879 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4561,15 +4561,16 @@  static int vcpu_ioctl_tpr_access_reporting(struct kvm_vcpu *vcpu,
 static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu *vcpu,
 					u64 mcg_cap)
 {
-	int r;
 	unsigned bank_num = mcg_cap & 0xff, bank;
 
-	r = -EINVAL;
+	if (vcpu->kvm->arch.mce_injection_disallowed)
+		return -EINVAL;
+
 	if (!bank_num || bank_num > KVM_MAX_MCE_BANKS)
-		goto out;
+		return -EINVAL;
 	if (mcg_cap & ~(kvm_mce_cap_supported | 0xff | 0xff0000))
-		goto out;
-	r = 0;
+		return -EINVAL;
+
 	vcpu->arch.mcg_cap = mcg_cap;
 	/* Init IA32_MCG_CTL to all 1s */
 	if (mcg_cap & MCG_CTL_P)
@@ -4579,8 +4580,7 @@  static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu *vcpu,
 		vcpu->arch.mce_banks[bank*4] = ~(u64)0;
 
 	static_call(kvm_x86_setup_mce)(vcpu);
-out:
-	return r;
+	return 0;
 }
 
 static int kvm_vcpu_ioctl_x86_set_mce(struct kvm_vcpu *vcpu,