diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-11-08 07:16:01 -1000 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-11-08 07:16:01 -1000 |
| commit | 51b47860ad8058ae54e4789b5f9b253fd555d2e9 (patch) | |
| tree | 7c34b5f656354a39a52f0a4c7ec18c5448b6fb24 | |
| parent | 906bd684e4b1e517dd424a354744c5b0aebef8af (diff) | |
| parent | a373830f96db288a3eb43a8692b6bcd0bd88dfe1 (diff) | |
Merge tag 'powerpc-6.12-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fix from Madhavan Srinivasan:
- Fix spurious interrupts in Book3S HV Nested KVM
Thanks to Gautam Menghani.
* tag 'powerpc-6.12-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
KVM: PPC: Book3S HV: Mask off LPCR_MER for a vCPU before running it to avoid spurious interrupts
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index ba0492f9de65..ad8dc4ccdaab 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -4898,6 +4898,18 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit, BOOK3S_INTERRUPT_EXTERNAL, 0); else lpcr |= LPCR_MER; + } else { + /* + * L1's copy of L2's LPCR (vcpu->arch.vcore->lpcr) can get its MER bit + * unexpectedly set - for e.g. during NMI handling when all register + * states are synchronized from L0 to L1. L1 needs to inform L0 about + * MER=1 only when there are pending external interrupts. + * In the above if check, MER bit is set if there are pending + * external interrupts. Hence, explicity mask off MER bit + * here as otherwise it may generate spurious interrupts in L2 KVM + * causing an endless loop, which results in L2 guest getting hung. + */ + lpcr &= ~LPCR_MER; } } else if (vcpu->arch.pending_exceptions || vcpu->arch.doorbell_request || |