diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2021-05-28 12:07:36 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-06-10 15:12:13 +0300 |
| commit | 6d770e3fe9a120560cda66331ce5faa363400e97 (patch) | |
| tree | fe6a82b9ddb0ceaeed2a81c5066533e04bcfc60f /arch/powerpc/kvm/book3s_hv_p9_entry.c | |
| parent | c00366e2375408e43370cd7981af3354f7c83ed3 (diff) | |
| download | linux-6d770e3fe9a120560cda66331ce5faa363400e97.tar.xz | |
KVM: PPC: Book3S HV P9: Read machine check registers while MSR[RI] is 0
SRR0/1, DAR, DSISR must all be protected from machine check which can
clobber them. Ensure MSR[RI] is clear while they are live.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-17-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/kvm/book3s_hv_p9_entry.c')
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_p9_entry.c | 33 |
1 files changed, 30 insertions, 3 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c index d2e659940630..a6f89e30040b 100644 --- a/arch/powerpc/kvm/book3s_hv_p9_entry.c +++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c @@ -122,6 +122,7 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc s64 hdec; u64 tb, purr, spurr; u64 *exsave; + bool ri_set; unsigned long msr = mfmsr(); int trap; unsigned long host_hfscr = mfspr(SPRN_HFSCR); @@ -192,9 +193,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc */ mtspr(SPRN_HDEC, hdec); - mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0); - mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1); - start_timing(vcpu, &vcpu->arch.rm_entry); vcpu->arch.ceded = 0; @@ -220,6 +218,13 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc */ mtspr(SPRN_HDSISR, HDSISR_CANARY); + __mtmsrd(0, 1); /* clear RI */ + + mtspr(SPRN_DAR, vcpu->arch.shregs.dar); + mtspr(SPRN_DSISR, vcpu->arch.shregs.dsisr); + mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0); + mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1); + accumulate_time(vcpu, &vcpu->arch.guest_time); local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_HV_FAST; @@ -237,7 +242,13 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc /* 0x2 bit for HSRR is only used by PR and P7/8 HV paths, clear it */ trap = local_paca->kvm_hstate.scratch0 & ~0x2; + + /* HSRR interrupts leave MSR[RI] unchanged, SRR interrupts clear it. */ + ri_set = false; if (likely(trap > BOOK3S_INTERRUPT_MACHINE_CHECK)) { + if (trap != BOOK3S_INTERRUPT_SYSCALL && + (vcpu->arch.shregs.msr & MSR_RI)) + ri_set = true; exsave = local_paca->exgen; } else if (trap == BOOK3S_INTERRUPT_SYSTEM_RESET) { exsave = local_paca->exnmi; @@ -247,6 +258,22 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc vcpu->arch.regs.gpr[1] = local_paca->kvm_hstate.scratch1; vcpu->arch.regs.gpr[3] = local_paca->kvm_hstate.scratch2; + + /* + * Only set RI after reading machine check regs (DAR, DSISR, SRR0/1) + * and hstate scratch (which we need to move into exsave to make + * re-entrant vs SRESET/MCE) + */ + if (ri_set) { + if (unlikely(!(mfmsr() & MSR_RI))) { + __mtmsrd(MSR_RI, 1); + WARN_ON_ONCE(1); + } + } else { + WARN_ON_ONCE(mfmsr() & MSR_RI); + __mtmsrd(MSR_RI, 1); + } + vcpu->arch.regs.gpr[9] = exsave[EX_R9/sizeof(u64)]; vcpu->arch.regs.gpr[10] = exsave[EX_R10/sizeof(u64)]; vcpu->arch.regs.gpr[11] = exsave[EX_R11/sizeof(u64)]; |