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authorRavi Bangoria <ravi.bangoria@amd.com>2024-05-31 07:46:43 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-06-21 15:38:15 +0300
commit2128bae4ecabff2fa232f91ebf9421c767ce7e77 (patch)
treef541759559257733d33d850b059bbeb4956cd71f
parent91cff53136daeff50816b0baeafd38a6976f6209 (diff)
downloadlinux-2128bae4ecabff2fa232f91ebf9421c767ce7e77.tar.xz
KVM: SEV-ES: Disallow SEV-ES guests when X86_FEATURE_LBRV is absent
[ Upstream commit d922056215617eedfbdbc29fe49953423686fe5e ] As documented in APM[1], LBR Virtualization must be enabled for SEV-ES guests. So, prevent SEV-ES guests when LBRV support is missing. [1]: AMD64 Architecture Programmer's Manual Pub. 40332, Rev. 4.07 - June 2023, Vol 2, 15.35.2 Enabling SEV-ES. https://bugzilla.kernel.org/attachment.cgi?id=304653 Fixes: 376c6d285017 ("KVM: SVM: Provide support for SEV-ES vCPU creation/loading") Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com> Message-ID: <20240531044644.768-3-ravi.bangoria@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--arch/x86/kvm/svm/sev.c6
-rw-r--r--arch/x86/kvm/svm/svm.c16
-rw-r--r--arch/x86/kvm/svm/svm.h1
3 files changed, 14 insertions, 9 deletions
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index c5845f31c34d..0e643d7a06d9 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2264,6 +2264,12 @@ void __init sev_hardware_setup(void)
if (!boot_cpu_has(X86_FEATURE_SEV_ES))
goto out;
+ if (!lbrv) {
+ WARN_ONCE(!boot_cpu_has(X86_FEATURE_LBRV),
+ "LBRV must be present for SEV-ES support");
+ goto out;
+ }
+
/* Has the system been allocated ASIDs for SEV-ES? */
if (min_sev_asid == 1)
goto out;
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 1efbe8b33f6a..9e084e22a12f 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -214,7 +214,7 @@ int vgif = true;
module_param(vgif, int, 0444);
/* enable/disable LBR virtualization */
-static int lbrv = true;
+int lbrv = true;
module_param(lbrv, int, 0444);
static int tsc_scaling = true;
@@ -5248,6 +5248,12 @@ static __init int svm_hardware_setup(void)
nrips = nrips && boot_cpu_has(X86_FEATURE_NRIPS);
+ if (lbrv) {
+ if (!boot_cpu_has(X86_FEATURE_LBRV))
+ lbrv = false;
+ else
+ pr_info("LBR virtualization supported\n");
+ }
/*
* Note, SEV setup consumes npt_enabled and enable_mmio_caching (which
* may be modified by svm_adjust_mmio_mask()), as well as nrips.
@@ -5301,14 +5307,6 @@ static __init int svm_hardware_setup(void)
svm_x86_ops.set_vnmi_pending = NULL;
}
-
- if (lbrv) {
- if (!boot_cpu_has(X86_FEATURE_LBRV))
- lbrv = false;
- else
- pr_info("LBR virtualization supported\n");
- }
-
if (!enable_pmu)
pr_info("PMU virtualization is disabled\n");
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index be67ab7fdd10..53bc4b0e388b 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -39,6 +39,7 @@ extern int vgif;
extern bool intercept_smi;
extern bool x2avic_enabled;
extern bool vnmi;
+extern int lbrv;
/*
* Clean bits in VMCB.