From: Chao Gao <chao.gao@intel.com>
To: Manali Shukla <manali.shukla@amd.com>
Cc: <kvm@vger.kernel.org>, <seanjc@google.com>,
<linux-doc@vger.kernel.org>, <linux-perf-users@vger.kernel.org>,
<x86@kernel.org>, <pbonzini@redhat.com>, <peterz@infradead.org>,
<bp@alien8.de>, <santosh.shukla@amd.com>, <ravi.bangoria@amd.com>,
<thomas.lendacky@amd.com>, <nikunj@amd.com>
Subject: Re: [PATCH 09/13] KVM: SVM: add support for IBS virtualization for non SEV-ES guests
Date: Tue, 12 Sep 2023 11:09:06 +0800 [thread overview]
Message-ID: <ZP/WUpKgpqMRiEpZ@chao-email> (raw)
In-Reply-To: <20230904095347.14994-10-manali.shukla@amd.com>
On Mon, Sep 04, 2023 at 09:53:43AM +0000, Manali Shukla wrote:
>@@ -1207,6 +1241,29 @@ static inline void init_vmcb_after_set_cpuid(struct kvm_vcpu *vcpu)
> /* No need to intercept these MSRs */
> set_msr_interception(vcpu, svm->msrpm, MSR_IA32_SYSENTER_EIP, 1, 1);
> set_msr_interception(vcpu, svm->msrpm, MSR_IA32_SYSENTER_ESP, 1, 1);
>+
>+ /*
>+ * If hardware supports VIBS then no need to intercept IBS MSRS
>+ * when VIBS is enabled in guest.
>+ */
>+ if (vibs) {
>+ if (guest_cpuid_has(&svm->vcpu, X86_FEATURE_IBS)) {
>+ svm_ibs_msr_interception(svm, false);
>+ svm->ibs_enabled = true;
>+
>+ /*
>+ * In order to enable VIBS, AVIC/VNMI must be enabled to handle the
>+ * interrupt generated by IBS driver. When AVIC is enabled, once
>+ * data collection for IBS fetch/op block for sampled interval
>+ * provided is done, hardware signals VNMI which is generated via
>+ * AVIC which uses extended LVT registers. That is why extended LVT
>+ * registers are initialized at guest startup.
>+ */
>+ kvm_apic_init_eilvt_regs(vcpu);
>+ } else {
>+ svm->ibs_enabled = false;
The interception should be enabled for IBS MSRs in the else branch. see:
https://lore.kernel.org/all/ZJYzPn7ipYfO0fLZ@google.com/
>+ }
>+ }
> }
> }
>
>@@ -2888,6 +2945,11 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
> case MSR_AMD64_DE_CFG:
> msr_info->data = svm->msr_decfg;
> break;
>+
>+ case MSR_AMD64_IBSCTL:
>+ rdmsrl(MSR_AMD64_IBSCTL, msr_info->data);
>+ break;
"When AVIC is enabled, IBS LVT entry (Extended Interrupt 0 LVT) message type
should be programmed to INTR or NMI."
It implies that AVIC always uses extended LVT 0 when issuing IBS interrupts if
IBS virtualization is enabled. Right? If yes, KVM should emulate the LvtOffset
in guest's IBS_CTL MSR as 0. Returning the hardware value here is error-prone.
next prev parent reply other threads:[~2023-09-12 3:26 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-04 9:53 [PATCH 00/13] Implement support for IBS virtualization Manali Shukla
2023-09-04 9:53 ` [PATCH 01/13] KVM: Add KVM_GET_LAPIC_W_EXTAPIC and KVM_SET_LAPIC_W_EXTAPIC for extapic Manali Shukla
2023-09-12 1:47 ` Chao Gao
2023-09-04 9:53 ` [PATCH 02/13] x86/cpufeatures: Add CPUID feature bit for Extended LVT Manali Shukla
2023-09-04 9:53 ` [PATCH 03/13] KVM: x86: Add emulation support for Extented LVT registers Manali Shukla
2023-09-12 2:36 ` Chao Gao
2023-09-04 9:53 ` [PATCH 04/13] x86/cpufeatures: Add CPUID feature bit for virtualized IBS Manali Shukla
2023-09-04 9:53 ` [PATCH 05/13] KVM: x86/cpuid: Add a KVM-only leaf for IBS capabilities Manali Shukla
2023-09-04 9:53 ` [PATCH 06/13] KVM: x86: Extend CPUID range to include new leaf Manali Shukla
2023-09-12 2:46 ` Chao Gao
2023-09-04 9:53 ` [PATCH 07/13] KVM: SVM: Extend VMCB area for virtualized IBS registers Manali Shukla
2023-09-12 2:50 ` Chao Gao
2023-09-04 9:53 ` [PATCH 08/13] perf/x86/amd: Add framework to save/restore host IBS state Manali Shukla
2023-09-05 14:54 ` Tom Lendacky
2023-09-04 9:53 ` [PATCH 09/13] KVM: SVM: add support for IBS virtualization for non SEV-ES guests Manali Shukla
2023-09-05 15:30 ` Tom Lendacky
2023-09-06 1:51 ` Alexey Kardashevskiy
2023-09-12 3:09 ` Chao Gao [this message]
2023-09-04 9:53 ` [PATCH 10/13] x86/cpufeatures: Add CPUID feature bit for VIBS in SEV-ES guest Manali Shukla
2023-09-04 9:53 ` [PATCH 11/13] KVM: SVM: Add support for IBS virtualization for SEV-ES guests Manali Shukla
2023-09-05 15:43 ` Tom Lendacky
2023-09-04 9:53 ` [PATCH 12/13] KVM: SVM: Enable IBS virtualization on non SEV-ES and " Manali Shukla
2023-09-05 16:00 ` Tom Lendacky
2023-09-12 3:30 ` Chao Gao
2023-09-04 9:53 ` [PATCH 13/13] KVM: x86: nSVM: Implement support for nested IBS virtualization Manali Shukla
2023-09-05 15:47 ` [PATCH 00/13] Implement support for " Peter Zijlstra
2023-09-06 15:38 ` Manali Shukla
2023-09-06 19:56 ` Peter Zijlstra
2023-09-07 15:49 ` Manali Shukla
2023-09-08 13:31 ` Peter Zijlstra
2023-09-11 12:32 ` Manali Shukla
2023-09-28 11:18 ` Manali Shukla
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