6.9-stable review patch. If anyone has any objections, please let me know.
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From: Ravi Bangoria ravi.bangoria@amd.com
[ 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 --- arch/x86/kvm/svm/sev.c | 6 ++++++ arch/x86/kvm/svm/svm.c | 16 +++++++--------- arch/x86/kvm/svm/svm.h | 1 + 3 files changed, 14 insertions(+), 9 deletions(-)
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 759581bb2128d..43b7d76a27a56 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -2269,6 +2269,12 @@ 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 308416b50b036..3363e5ba0fff5 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -215,7 +215,7 @@ 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; @@ -5260,6 +5260,12 @@ 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. @@ -5313,14 +5319,6 @@ 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 33878efdebc82..4bf9af529ae03 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.