From: <gregkh@linuxfoundation.org>
To: mlevitsk@redhat.com,dapeng1.mi@linux.intel.com,seanjc@google.com
Cc: <stable@vger.kernel.org>
Subject: FAILED: patch "[PATCH] KVM: VMX: Wrap all accesses to IA32_DEBUGCTL with" failed to apply to 6.6-stable tree
Date: Tue, 12 Aug 2025 18:15:14 +0200 [thread overview]
Message-ID: <2025081214-bonanza-germproof-173f@gregkh> (raw)
The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 7d0cce6cbe71af6e9c1831bff101a2b9c249c4a2
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025081214-bonanza-germproof-173f@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 7d0cce6cbe71af6e9c1831bff101a2b9c249c4a2 Mon Sep 17 00:00:00 2001
From: Maxim Levitsky <mlevitsk@redhat.com>
Date: Tue, 10 Jun 2025 16:20:09 -0700
Subject: [PATCH] KVM: VMX: Wrap all accesses to IA32_DEBUGCTL with
getter/setter APIs
Introduce vmx_guest_debugctl_{read,write}() to handle all accesses to
vmcs.GUEST_IA32_DEBUGCTL. This will allow stuffing FREEZE_IN_SMM into
GUEST_IA32_DEBUGCTL based on the host setting without bleeding the state
into the guest, and without needing to copy+paste the FREEZE_IN_SMM
logic into every patch that accesses GUEST_IA32_DEBUGCTL.
No functional change intended.
Cc: stable@vger.kernel.org
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
[sean: massage changelog, make inline, use in all prepare_vmcs02() cases]
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Link: https://lore.kernel.org/r/20250610232010.162191-8-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 1b8b0642fc2d..ef20184b8b11 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -2663,11 +2663,11 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
if (vmx->nested.nested_run_pending &&
(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS)) {
kvm_set_dr(vcpu, 7, vmcs12->guest_dr7);
- vmcs_write64(GUEST_IA32_DEBUGCTL, vmcs12->guest_ia32_debugctl &
- vmx_get_supported_debugctl(vcpu, false));
+ vmx_guest_debugctl_write(vcpu, vmcs12->guest_ia32_debugctl &
+ vmx_get_supported_debugctl(vcpu, false));
} else {
kvm_set_dr(vcpu, 7, vcpu->arch.dr7);
- vmcs_write64(GUEST_IA32_DEBUGCTL, vmx->nested.pre_vmenter_debugctl);
+ vmx_guest_debugctl_write(vcpu, vmx->nested.pre_vmenter_debugctl);
}
if (kvm_mpx_supported() && (!vmx->nested.nested_run_pending ||
!(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS)))
@@ -3532,7 +3532,7 @@ enum nvmx_vmentry_status nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu,
if (!vmx->nested.nested_run_pending ||
!(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS))
- vmx->nested.pre_vmenter_debugctl = vmcs_read64(GUEST_IA32_DEBUGCTL);
+ vmx->nested.pre_vmenter_debugctl = vmx_guest_debugctl_read();
if (kvm_mpx_supported() &&
(!vmx->nested.nested_run_pending ||
!(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS)))
@@ -4806,7 +4806,7 @@ static void load_vmcs12_host_state(struct kvm_vcpu *vcpu,
__vmx_set_segment(vcpu, &seg, VCPU_SREG_LDTR);
kvm_set_dr(vcpu, 7, 0x400);
- vmcs_write64(GUEST_IA32_DEBUGCTL, 0);
+ vmx_guest_debugctl_write(vcpu, 0);
if (nested_vmx_load_msr(vcpu, vmcs12->vm_exit_msr_load_addr,
vmcs12->vm_exit_msr_load_count))
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index bbf4509f32d0..0b173602821b 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -653,11 +653,11 @@ static void intel_pmu_reset(struct kvm_vcpu *vcpu)
*/
static void intel_pmu_legacy_freezing_lbrs_on_pmi(struct kvm_vcpu *vcpu)
{
- u64 data = vmcs_read64(GUEST_IA32_DEBUGCTL);
+ u64 data = vmx_guest_debugctl_read();
if (data & DEBUGCTLMSR_FREEZE_LBRS_ON_PMI) {
data &= ~DEBUGCTLMSR_LBR;
- vmcs_write64(GUEST_IA32_DEBUGCTL, data);
+ vmx_guest_debugctl_write(vcpu, data);
}
}
@@ -730,7 +730,7 @@ void vmx_passthrough_lbr_msrs(struct kvm_vcpu *vcpu)
if (!lbr_desc->event) {
vmx_disable_lbr_msrs_passthrough(vcpu);
- if (vmcs_read64(GUEST_IA32_DEBUGCTL) & DEBUGCTLMSR_LBR)
+ if (vmx_guest_debugctl_read() & DEBUGCTLMSR_LBR)
goto warn;
if (test_bit(INTEL_PMC_IDX_FIXED_VLBR, pmu->pmc_in_use))
goto warn;
@@ -752,7 +752,7 @@ void vmx_passthrough_lbr_msrs(struct kvm_vcpu *vcpu)
static void intel_pmu_cleanup(struct kvm_vcpu *vcpu)
{
- if (!(vmcs_read64(GUEST_IA32_DEBUGCTL) & DEBUGCTLMSR_LBR))
+ if (!(vmx_guest_debugctl_read() & DEBUGCTLMSR_LBR))
intel_pmu_release_guest_lbr_event(vcpu);
}
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 6a8b78e954cd..a77d325fe78b 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2149,7 +2149,7 @@ int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
msr_info->data = vmx->pt_desc.guest.addr_a[index / 2];
break;
case MSR_IA32_DEBUGCTLMSR:
- msr_info->data = vmcs_read64(GUEST_IA32_DEBUGCTL);
+ msr_info->data = vmx_guest_debugctl_read();
break;
default:
find_uret_msr:
@@ -2283,7 +2283,8 @@ int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
VM_EXIT_SAVE_DEBUG_CONTROLS)
get_vmcs12(vcpu)->guest_ia32_debugctl = data;
- vmcs_write64(GUEST_IA32_DEBUGCTL, data);
+ vmx_guest_debugctl_write(vcpu, data);
+
if (intel_pmu_lbr_is_enabled(vcpu) && !to_vmx(vcpu)->lbr_desc.event &&
(data & DEBUGCTLMSR_LBR))
intel_pmu_create_guest_lbr_event(vcpu);
@@ -4798,7 +4799,8 @@ static void init_vmcs(struct vcpu_vmx *vmx)
vmcs_write32(GUEST_SYSENTER_CS, 0);
vmcs_writel(GUEST_SYSENTER_ESP, 0);
vmcs_writel(GUEST_SYSENTER_EIP, 0);
- vmcs_write64(GUEST_IA32_DEBUGCTL, 0);
+
+ vmx_guest_debugctl_write(&vmx->vcpu, 0);
if (cpu_has_vmx_tpr_shadow()) {
vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, 0);
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 392e66c7e5fe..c20a4185d10a 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -417,6 +417,16 @@ void vmx_update_cpu_dirty_logging(struct kvm_vcpu *vcpu);
u64 vmx_get_supported_debugctl(struct kvm_vcpu *vcpu, bool host_initiated);
bool vmx_is_valid_debugctl(struct kvm_vcpu *vcpu, u64 data, bool host_initiated);
+static inline void vmx_guest_debugctl_write(struct kvm_vcpu *vcpu, u64 val)
+{
+ vmcs_write64(GUEST_IA32_DEBUGCTL, val);
+}
+
+static inline u64 vmx_guest_debugctl_read(void)
+{
+ return vmcs_read64(GUEST_IA32_DEBUGCTL);
+}
+
/*
* Note, early Intel manuals have the write-low and read-high bitmap offsets
* the wrong way round. The bitmaps control MSRs 0x00000000-0x00001fff and
next reply other threads:[~2025-08-12 16:15 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-12 16:15 gregkh [this message]
2025-08-14 13:11 ` [PATCH 6.6.y 1/3] KVM: VMX: Extract checking of guest's DEBUGCTL into helper Sasha Levin
2025-08-14 13:11 ` [PATCH 6.6.y 2/3] KVM: nVMX: Check vmcs12->guest_ia32_debugctl on nested VM-Enter Sasha Levin
2025-08-14 19:05 ` Sean Christopherson
2025-08-14 13:11 ` [PATCH 6.6.y 3/3] KVM: VMX: Wrap all accesses to IA32_DEBUGCTL with getter/setter APIs Sasha Levin
2025-08-14 19:05 ` Sean Christopherson
2025-08-14 19:04 ` [PATCH 6.6.y 1/3] KVM: VMX: Extract checking of guest's DEBUGCTL into helper Sean Christopherson
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=2025081214-bonanza-germproof-173f@gregkh \
--to=gregkh@linuxfoundation.org \
--cc=dapeng1.mi@linux.intel.com \
--cc=mlevitsk@redhat.com \
--cc=seanjc@google.com \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).