summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kvm
diff options
context:
space:
mode:
authorNicholas Piggin2017-01-27 05:00:34 +0100
committerMichael Ellerman2017-01-31 09:07:39 +0100
commita97a65d53d9f53b6897dc1b2aed381bc1707136b (patch)
tree08dcf2d0b98a978d80bf09dc5f6829e9831c7bb5 /arch/powerpc/kvm
parentKVM: PPC: Book3S: Move 64-bit KVM interrupt handler out from alt section (diff)
downloadkernel-qcow2-linux-a97a65d53d9f53b6897dc1b2aed381bc1707136b.tar.gz
kernel-qcow2-linux-a97a65d53d9f53b6897dc1b2aed381bc1707136b.tar.xz
kernel-qcow2-linux-a97a65d53d9f53b6897dc1b2aed381bc1707136b.zip
KVM: PPC: Book3S: 64-bit CONFIG_RELOCATABLE support for interrupts
64-bit Book3S exception handlers must find the dynamic kernel base to add to the target address when branching beyond __end_interrupts, in order to support kernel running at non-0 physical address. Support this in KVM by branching with CTR, similarly to regular interrupt handlers. The guest CTR saved in HSTATE_SCRATCH1 and restored after the branch. Without this, the host kernel hangs and crashes randomly when it is running at a non-0 address and a KVM guest is started. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kvm')
-rw-r--r--arch/powerpc/kvm/book3s_hv_rmhandlers.S12
-rw-r--r--arch/powerpc/kvm/book3s_segment.S7
2 files changed, 16 insertions, 3 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 11882aac8216..264ac9ad4585 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1060,15 +1060,16 @@ kvmppc_interrupt_hv:
* R12 = (guest CR << 32) | interrupt vector
* R13 = PACA
* guest R12 saved in shadow VCPU SCRATCH0
+ * guest CTR saved in shadow VCPU SCRATCH1 if RELOCATABLE
* guest R13 saved in SPRN_SCRATCH0
*/
- std r9, HSTATE_SCRATCH1(r13)
+ std r9, HSTATE_SCRATCH2(r13)
lbz r9, HSTATE_IN_GUEST(r13)
cmpwi r9, KVM_GUEST_MODE_HOST_HV
beq kvmppc_bad_host_intr
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
cmpwi r9, KVM_GUEST_MODE_GUEST
- ld r9, HSTATE_SCRATCH1(r13)
+ ld r9, HSTATE_SCRATCH2(r13)
beq kvmppc_interrupt_pr
#endif
/* We're now back in the host but in guest MMU context */
@@ -1088,7 +1089,7 @@ kvmppc_interrupt_hv:
std r6, VCPU_GPR(R6)(r9)
std r7, VCPU_GPR(R7)(r9)
std r8, VCPU_GPR(R8)(r9)
- ld r0, HSTATE_SCRATCH1(r13)
+ ld r0, HSTATE_SCRATCH2(r13)
std r0, VCPU_GPR(R9)(r9)
std r10, VCPU_GPR(R10)(r9)
std r11, VCPU_GPR(R11)(r9)
@@ -1151,7 +1152,12 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
11: stw r3,VCPU_HEIR(r9)
/* these are volatile across C function calls */
+#ifdef CONFIG_RELOCATABLE
+ ld r3, HSTATE_SCRATCH1(r13)
+ mtctr r3
+#else
mfctr r3
+#endif
mfxer r4
std r3, VCPU_CTR(r9)
std r4, VCPU_XER(r9)
diff --git a/arch/powerpc/kvm/book3s_segment.S b/arch/powerpc/kvm/book3s_segment.S
index 68e45080cf93..2a2b96d53999 100644
--- a/arch/powerpc/kvm/book3s_segment.S
+++ b/arch/powerpc/kvm/book3s_segment.S
@@ -175,9 +175,16 @@ kvmppc_interrupt_pr:
* R12 = (guest CR << 32) | exit handler id
* R13 = PACA
* HSTATE.SCRATCH0 = guest R12
+ * HSTATE.SCRATCH1 = guest CTR if RELOCATABLE
*/
#ifdef CONFIG_PPC64
/* Match 32-bit entry */
+#ifdef CONFIG_RELOCATABLE
+ std r9, HSTATE_SCRATCH2(r13)
+ ld r9, HSTATE_SCRATCH1(r13)
+ mtctr r9
+ ld r9, HSTATE_SCRATCH2(r13)
+#endif
rotldi r12, r12, 32 /* Flip R12 halves for stw */
stw r12, HSTATE_SCRATCH1(r13) /* CR is now in the low half */
srdi r12, r12, 32 /* shift trap into low half */