This is a note to let you know that I've just added the patch titled
KVM: nVMX: Don't propagate vmcs12's PERF_GLOBAL_CTRL settings to vmcs02
to the 6.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-nvmx-don-t-propagate-vmcs12-s-perf_global_ctrl-settings-to-vmcs02.patch
and it can be found in the queue-6.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From def9d705c05eab3fdedeb10ad67907513b12038e Mon Sep 17 00:00:00 2001
From: Sean Christopherson <seanjc@xxxxxxxxxx>
Date: Tue, 30 Aug 2022 15:37:21 +0200
Subject: KVM: nVMX: Don't propagate vmcs12's PERF_GLOBAL_CTRL settings to vmcs02
From: Sean Christopherson <seanjc@xxxxxxxxxx>
commit def9d705c05eab3fdedeb10ad67907513b12038e upstream.
Don't propagate vmcs12's VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL to vmcs02.
KVM doesn't disallow L1 from using VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL
even when KVM itself doesn't use the control, e.g. due to the various
CPU errata that where the MSR can be corrupted on VM-Exit.
Preserve KVM's (vmcs01) setting to hopefully avoid having to toggle the
bit in vmcs02 at a later point. E.g. if KVM is loading PERF_GLOBAL_CTRL
when running L1, then odds are good KVM will also load the MSR when
running L2.
Fixes: 8bf00a529967 ("KVM: VMX: add support for switching of PERF_GLOBAL_CTRL")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220830133737.1539624-18-vkuznets@xxxxxxxxxx
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/vmx/nested.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -2328,9 +2328,14 @@ static void prepare_vmcs02_early(struct
* are emulated by vmx_set_efer() in prepare_vmcs02(), but speculate
* on the related bits (if supported by the CPU) in the hope that
* we can avoid VMWrites during vmx_set_efer().
+ *
+ * Similarly, take vmcs01's PERF_GLOBAL_CTRL in the hope that if KVM is
+ * loading PERF_GLOBAL_CTRL via the VMCS for L1, then KVM will want to
+ * do the same for L2.
*/
exec_control = __vm_entry_controls_get(vmcs01);
- exec_control |= vmcs12->vm_entry_controls;
+ exec_control |= (vmcs12->vm_entry_controls &
+ ~VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL);
exec_control &= ~(VM_ENTRY_IA32E_MODE | VM_ENTRY_LOAD_IA32_EFER);
if (cpu_has_load_ia32_efer()) {
if (guest_efer & EFER_LMA)
Patches currently in stable-queue which might be from seanjc@xxxxxxxxxx are
queue-6.0/kvm-nvmx-unconditionally-purge-queued-injected-events-on-nested-exit.patch
queue-6.0/kvm-vmx-drop-bits-31-16-when-shoving-exception-error-code-into-vmcs.patch
queue-6.0/kvm-nvmx-don-t-propagate-vmcs12-s-perf_global_ctrl-settings-to-vmcs02.patch
queue-6.0/kvm-x86-emulator-fix-handing-of-pop-ss-to-correctly-set-interruptibility.patch
queue-6.0/kvm-x86-treat-dbs-from-the-emulator-as-fault-like-code-and-dr7.gd-1.patch
