KVM: x86: fix presentation of TSX feature in ARCH_CAPABILITIES (cbbaa272) · Commits · 戴 / test

KVM does not implement MSR_IA32_TSX_CTRL, so it must not be presented to the guests. It is also confusing to have !ARCH_CAP_TSX_CTRL_MSR && !RTM && ARCH_CAP_TAA_NO: lack of MSR_IA32_TSX_CTRL suggests TSX was not hidden (it actually was), yet the value says that TSX is not vulnerable to microarchitectural data sampling. Fix both. Cc: stable@vger.kernel.org Tested-by:

Jim Mattson <jmattson@google.com> Signed-off-by:

Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/x86.c

+8 −2

Original line number	Diff line number	Diff line
		@@ -1327,12 +1327,18 @@ static u64 kvm_get_arch_capabilities(void)
		* If TSX is disabled on the system, guests are also mitigated against
		* TAA and clear CPU buffer mitigation is not required for guests.
		*/
		if (boot_cpu_has_bug(X86_BUG_TAA) && boot_cpu_has(X86_FEATURE_RTM) &&
		(data & ARCH_CAP_TSX_CTRL_MSR))
		if (!boot_cpu_has(X86_FEATURE_RTM))
		data &= ~ARCH_CAP_TAA_NO;
		else if (!boot_cpu_has_bug(X86_BUG_TAA))
		data \|= ARCH_CAP_TAA_NO;
		else if (data & ARCH_CAP_TSX_CTRL_MSR)
		data &= ~ARCH_CAP_MDS_NO;

		/* KVM does not emulate MSR_IA32_TSX_CTRL. */
		data &= ~ARCH_CAP_TSX_CTRL_MSR;
		return data;
		}
		EXPORT_SYMBOL_GPL(kvm_get_arch_capabilities);

		static int kvm_get_msr_feature(struct kvm_msr_entry *msr)
		{

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