From 2128bae4ecabff2fa232f91ebf9421c767ce7e77 Mon Sep 17 00:00:00 2001 From: Ravi Bangoria Date: Fri, 31 May 2024 04:46:43 +0000 Subject: 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 Message-ID: <20240531044644.768-3-ravi.bangoria@amd.com> Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin --- 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 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. -- cgit v1.2.3