From: Ravi Bangoria <ravi.bangoria@amd.com>
To: <tglx@linutronix.de>, <mingo@redhat.com>, <bp@alien8.de>,
<dave.hansen@linux.intel.com>, <seanjc@google.com>,
<pbonzini@redhat.com>, <thomas.lendacky@amd.com>
Cc: <ravi.bangoria@amd.com>, <hpa@zytor.com>,
<rmk+kernel@armlinux.org.uk>, <peterz@infradead.org>,
<james.morse@arm.com>, <lukas.bulwahn@gmail.com>,
<arjan@linux.intel.com>, <j.granados@samsung.com>,
<sibs@chinatelecom.cn>, <nik.borisov@suse.com>,
<michael.roth@amd.com>, <nikunj.dadhania@amd.com>,
<babu.moger@amd.com>, <x86@kernel.org>, <kvm@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, <santosh.shukla@amd.com>,
<ananth.narayan@amd.com>, <sandipan.das@amd.com>
Subject: [PATCH 3/3] KVM SVM: Add Bus Lock Detect support
Date: Mon, 29 Apr 2024 11:36:43 +0530 [thread overview]
Message-ID: <20240429060643.211-4-ravi.bangoria@amd.com> (raw)
In-Reply-To: <20240429060643.211-1-ravi.bangoria@amd.com>
Upcoming AMD uarch will support Bus Lock Detect. Add support for it
in KVM. Bus Lock Detect is enabled through MSR_IA32_DEBUGCTLMSR and
MSR_IA32_DEBUGCTLMSR is virtualized only if LBR Virtualization is
enabled. Add this dependency in the KVM.
Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
---
arch/x86/kvm/svm/nested.c | 3 ++-
arch/x86/kvm/svm/svm.c | 16 +++++++++++++++-
2 files changed, 17 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 55b9a6d96bcf..6e93c2d9e7df 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -586,7 +586,8 @@ static void nested_vmcb02_prepare_save(struct vcpu_svm *svm, struct vmcb *vmcb12
/* These bits will be set properly on the first execution when new_vmc12 is true */
if (unlikely(new_vmcb12 || vmcb_is_dirty(vmcb12, VMCB_DR))) {
vmcb02->save.dr7 = svm->nested.save.dr7 | DR7_FIXED_1;
- svm->vcpu.arch.dr6 = svm->nested.save.dr6 | DR6_ACTIVE_LOW;
+ /* DR6_RTM is not supported on AMD as of now. */
+ svm->vcpu.arch.dr6 = svm->nested.save.dr6 | DR6_FIXED_1 | DR6_RTM;
vmcb_mark_dirty(vmcb02, VMCB_DR);
}
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index d1a9f9951635..60f3af9bdacb 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1038,7 +1038,8 @@ void svm_update_lbrv(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
bool current_enable_lbrv = svm->vmcb->control.virt_ext & LBR_CTL_ENABLE_MASK;
- bool enable_lbrv = (svm_get_lbr_vmcb(svm)->save.dbgctl & DEBUGCTLMSR_LBR) ||
+ u64 dbgctl_buslock_lbr = DEBUGCTLMSR_BUS_LOCK_DETECT | DEBUGCTLMSR_LBR;
+ bool enable_lbrv = (svm_get_lbr_vmcb(svm)->save.dbgctl & dbgctl_buslock_lbr) ||
(is_guest_mode(vcpu) && guest_can_use(vcpu, X86_FEATURE_LBRV) &&
(svm->nested.ctl.virt_ext & LBR_CTL_ENABLE_MASK));
@@ -3119,6 +3120,10 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
if (data & DEBUGCTL_RESERVED_BITS)
return 1;
+ if ((data & DEBUGCTLMSR_BUS_LOCK_DETECT) &&
+ !guest_cpuid_has(vcpu, X86_FEATURE_BUS_LOCK_DETECT))
+ return 1;
+
svm_get_lbr_vmcb(svm)->save.dbgctl = data;
svm_update_lbrv(vcpu);
break;
@@ -5157,6 +5162,15 @@ static __init void svm_set_cpu_caps(void)
/* CPUID 0x8000001F (SME/SEV features) */
sev_set_cpu_caps();
+
+ /*
+ * LBR Virtualization must be enabled to support BusLockTrap inside the
+ * guest, since BusLockTrap is enabled through MSR_IA32_DEBUGCTLMSR and
+ * MSR_IA32_DEBUGCTLMSR is virtualized only if LBR Virtualization is
+ * enabled.
+ */
+ if (!lbrv)
+ kvm_cpu_cap_clear(X86_FEATURE_BUS_LOCK_DETECT);
}
static __init int svm_hardware_setup(void)
--
2.44.0
prev parent reply other threads:[~2024-04-29 6:07 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-29 6:06 [PATCH 0/3] x86/cpu: Add Bus Lock Detect support for AMD Ravi Bangoria
2024-04-29 6:06 ` [PATCH 1/3] x86/split_lock: Move Split and Bus lock code to a dedicated file Ravi Bangoria
2024-05-06 12:58 ` Borislav Petkov
2024-05-07 4:07 ` Ravi Bangoria
2024-04-29 6:06 ` [PATCH 2/3] x86/bus_lock: Add support for AMD Ravi Bangoria
2024-05-06 16:05 ` Tom Lendacky
2024-05-07 4:08 ` Ravi Bangoria
2024-05-06 16:24 ` Jim Mattson
2024-05-07 3:57 ` Ravi Bangoria
2024-04-29 6:06 ` Ravi Bangoria [this message]
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