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authorPaul Mackerras <paulus@ozlabs.org>2018-01-11 04:31:43 +0100
committerPaul Mackerras <paulus@ozlabs.org>2018-01-17 01:18:48 +0100
commit43ff3f65234061e08d234bdef5a9aadc19832b74 (patch)
tree803b7bfef4591b2c978e767746307b4ab16453cd /arch
parentKVM: PPC: Book3S HV: Enable migration of decrementer register (diff)
downloadlinux-43ff3f65234061e08d234bdef5a9aadc19832b74.tar.xz
linux-43ff3f65234061e08d234bdef5a9aadc19832b74.zip
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: stable@vger.kernel.org # v4.11+ Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/kvm/book3s_hv_rmhandlers.S40
1 files 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)
-
- /* 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
mr r3, r12
/* Increment exit count, poke other threads to exit */