KVM: PPC: Book3S HV: Make sure we don't re-enter guest without XIVE loaded
"Linux Kernel Mailing List" <[email protected]> Sat, 10 Feb 2018 22:00:25 +0000 (UTC)
| Newsgroups | gmane.linux.kernel.commits.head |
|---|---|
| Message-ID | <[email protected]> |
Web: https://git.kernel.org/torvalds/c/43ff3f65234061e08d234bdef5a9aadc19832b74 Commit: 43ff3f65234061e08d234bdef5a9aadc19832b74 Parent: 5855564c8ab2d9cefca7b2933bd19818eb795e40 Refname: refs/heads/master Author: Paul Mackerras <[email protected]> AuthorDate: Thu Jan 11 14:31:43 2018 +1100 Committer: Paul Mackerras <[email protected]> CommitDate: Wed Jan 17 11:18:48 2018 +1100 KVM: PPC: Book3S HV: Make sure we don't re-enter guest without XIVE loaded This fixes a bug where it is possible to enter a guest on a POWER9 system without having the XIVE (interrupt controller) context loaded. This can happen because we unload the XIVE context from the CPU before doing the real-mode handling for machine checks. After the real-mode handler runs, it is possible that we re-enter the guest via a fast path which does not load the XIVE context. To fix this, we move the unloading of the XIVE context to come after the real-mode machine check handler is called. Fixes: 5af50993850a ("KVM: PPC: Book3S HV: Native usage of the XIVE interrupt controller") Cc: [email protected] # v4.11+ Signed-off-by: Paul Mackerras <[email protected]> --- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 40 ++++++++++++++++----------------- 1 file changed, 20 insertions(+), 20 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index c8ffd69adfec..76332a3f6c0d 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -1423,6 +1423,26 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300) blt deliver_guest_interrupt guest_exit_cont: /* r9 = vcpu, r12 = trap, r13 = paca */ + /* Save more register state */ + mfdar r6 + mfdsisr r7 + std r6, VCPU_DAR(r9) + stw r7, VCPU_DSISR(r9) + /* don't overwrite fault_dar/fault_dsisr if HDSI */ + cmpwi r12,BOOK3S_INTERRUPT_H_DATA_STORAGE + beq mc_cont + std r6, VCPU_FAULT_DAR(r9) + stw r7, VCPU_FAULT_DSISR(r9) + + /* See if it is a machine check */ + cmpwi r12, BOOK3S_INTERRUPT_MACHINE_CHECK + beq machine_check_realmode +mc_cont: +#ifdef CONFIG_KVM_BOOK3S_HV_EXIT_TIMING + addi r3, r9, VCPU_TB_RMEXIT + mr r4, r9 + bl kvmhv_accumulate_time +#endif #ifdef CONFIG_KVM_XICS /* We are exiting, pull the VP from the XIVE */ lwz r0, VCPU_XIVE_PUSHED(r9) @@ -1460,26 +1480,6 @@ guest_exit_cont: /* r9 = vcpu, r12 = trap, r13 = paca */ eieio 1: #endif /* CONFIG_KVM_XICS */ - /* Save more register state */ - mfdar r6 - mfdsisr r7 - std r6, VCPU_DAR(r9) - stw r7, VCPU_DSISR(r9) - /* don't overwrite fault_dar/fault_dsisr if HDSI */ - cmpwi r12,BOOK3S_INTERRUPT_H_DATA_STORAGE - beq mc_cont - std r6, VCPU_FAULT_DAR(r9) - stw r7, VCPU_FAULT_DSISR(r9)