releases/4.9.162/svm-fix-avic-incomplete-ipi-emulation.patch

   1 From fcbe00c7276be22464570b598d42cbc108ff1d00 Mon Sep 17 00:00:00 2001
   2 From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
   3 Date: Tue, 22 Jan 2019 10:25:13 +0000
   4 Subject: svm: Fix AVIC incomplete IPI emulation
   5
   6 [ Upstream commit bb218fbcfaaa3b115d4cd7a43c0ca164f3a96e57 ]
   7
   8 In case of incomplete IPI with invalid interrupt type, the current
   9 SVM driver does not properly emulate the IPI, and fails to boot
  10 FreeBSD guests with multiple vcpus when enabling AVIC.
  11
  12 Fix this by update APIC ICR high/low registers, which also
  13 emulate sending the IPI.
  14
  15 Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
  16 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
  17 Signed-off-by: Sasha Levin <sashal@kernel.org>
  18 ---
  19  arch/x86/kvm/svm.c | 19 ++++---------------
  20  1 file changed, 4 insertions(+), 15 deletions(-)
  21
  22 diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
  23 index c8efacf2e65f1..afc2bd03b4d9e 100644
  24 --- a/arch/x86/kvm/svm.c
  25 +++ b/arch/x86/kvm/svm.c
  26 @@ -3932,25 +3932,14 @@ static int avic_incomplete_ipi_interception(struct vcpu_svm *svm)
  27                 kvm_lapic_reg_write(apic, APIC_ICR, icrl);
  28                 break;
  29         case AVIC_IPI_FAILURE_TARGET_NOT_RUNNING: {
  30 -               int i;
  31 -               struct kvm_vcpu *vcpu;
  32 -               struct kvm *kvm = svm->vcpu.kvm;
  33                 struct kvm_lapic *apic = svm->vcpu.arch.apic;
  34
  35                 /*
  36 -                * At this point, we expect that the AVIC HW has already
  37 -                * set the appropriate IRR bits on the valid target
  38 -                * vcpus. So, we just need to kick the appropriate vcpu.
  39 +                * Update ICR high and low, then emulate sending IPI,
  40 +                * which is handled when writing APIC_ICR.
  41                  */
  42 -               kvm_for_each_vcpu(i, vcpu, kvm) {
  43 -                       bool m = kvm_apic_match_dest(vcpu, apic,
  44 -                                                    icrl & KVM_APIC_SHORT_MASK,
  45 -                                                    GET_APIC_DEST_FIELD(icrh),
  46 -                                                    icrl & KVM_APIC_DEST_MASK);
  47 -
  48 -                       if (m && !avic_vcpu_is_running(vcpu))
  49 -                               kvm_vcpu_wake_up(vcpu);
  50 -               }
  51 +               kvm_lapic_reg_write(apic, APIC_ICR2, icrh);
  52 +               kvm_lapic_reg_write(apic, APIC_ICR, icrl);
  53                 break;
  54         }
  55         case AVIC_IPI_FAILURE_INVALID_TARGET:
  56 --
  57 2.19.1
  58