The patch below does not apply to the 6.1-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-6.1.y git checkout FETCH_HEAD git cherry-pick -x 27c4fa42b11af780d49ce704f7fa67b3c2544df4 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024072918-undivided-veneering-9883@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:

27c4fa42b11a ("KVM: nVMX: Check for pending posted interrupts when looking for nested events")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 27c4fa42b11af780d49ce704f7fa67b3c2544df4 Mon Sep 17 00:00:00 2001 From: Sean Christopherson seanjc@google.com Date: Fri, 7 Jun 2024 10:26:07 -0700 Subject: [PATCH] KVM: nVMX: Check for pending posted interrupts when looking for nested events

Check for pending (and notified!) posted interrupts when checking if L2 has a pending wake event, as fully posted/notified virtual interrupt is a valid wake event for HLT.

Note that KVM must check vmx->nested.pi_pending to avoid prematurely waking L2, e.g. even if KVM sees a non-zero PID.PIR and PID.0N=1, the virtual interrupt won't actually be recognized until a notification IRQ is received by the vCPU or the vCPU does (nested) VM-Enter.

Fixes: 26844fee6ade ("KVM: x86: never write to memory from kvm_vcpu_check_block()") Cc: stable@vger.kernel.org Cc: Maxim Levitsky mlevitsk@redhat.com Reported-by: Jim Mattson jmattson@google.com Closes: https://lore.kernel.org/all/20231207010302.2240506-1-jmattson@google.com Link: https://lore.kernel.org/r/20240607172609.3205077-5-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 411fe7aa0793..732340ff3300 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -4034,8 +4034,40 @@ static bool nested_vmx_preemption_timer_pending(struct kvm_vcpu *vcpu)

static bool vmx_has_nested_events(struct kvm_vcpu *vcpu, bool for_injection) { - return nested_vmx_preemption_timer_pending(vcpu) || - to_vmx(vcpu)->nested.mtf_pending; + struct vcpu_vmx *vmx = to_vmx(vcpu); + void *vapic = vmx->nested.virtual_apic_map.hva; + int max_irr, vppr; + + if (nested_vmx_preemption_timer_pending(vcpu) || + vmx->nested.mtf_pending) + return true; + + /* + * Virtual Interrupt Delivery doesn't require manual injection. Either + * the interrupt is already in GUEST_RVI and will be recognized by CPU + * at VM-Entry, or there is a KVM_REQ_EVENT pending and KVM will move + * the interrupt from the PIR to RVI prior to entering the guest. + */ + if (for_injection) + return false; + + if (!nested_cpu_has_vid(get_vmcs12(vcpu)) || + __vmx_interrupt_blocked(vcpu)) + return false; + + if (!vapic) + return false; + + vppr = *((u32 *)(vapic + APIC_PROCPRI)); + + if (vmx->nested.pi_pending && vmx->nested.pi_desc && + pi_test_on(vmx->nested.pi_desc)) { + max_irr = pi_find_highest_vector(vmx->nested.pi_desc); + if (max_irr > 0 && (max_irr & 0xf0) > (vppr & 0xf0)) + return true; + } + + return false; }

/*