Similar to commit 25edcc50d76c ("KVM: PPC: Book3S HV: Save and restore
FSCR in the P9 path"), ensure the P7/8 path saves and restores the host
FSCR. The logic explained in that patch actually applies there to the
old path well: a context switch can be made before kvmppc_vcpu_run_hv
restores the host FSCR and returns.
Fixes: b005255e12a3 ("KVM: PPC: Book3S HV: Context-switch new POWER8 SPRs")
Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 5e634db4809b..2b98e710c7a1 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -44,7 +44,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
#define NAPPING_UNSPLIT 3
/* Stack frame offsets for kvmppc_hv_entry */
-#define SFS 208
+#define SFS 216
#define STACK_SLOT_TRAP (SFS-4)
#define STACK_SLOT_SHORT_PATH (SFS-8)
#define STACK_SLOT_TID (SFS-16)
@@ -59,8 +59,9 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
#define STACK_SLOT_UAMOR (SFS-88)
#define STACK_SLOT_DAWR1 (SFS-96)
#define STACK_SLOT_DAWRX1 (SFS-104)
+#define STACK_SLOT_FSCR (SFS-112)
/* the following is used by the P9 short path */
-#define STACK_SLOT_NVGPRS (SFS-152) /* 18 gprs */
+#define STACK_SLOT_NVGPRS (SFS-160) /* 18 gprs */
/*
* Call kvmppc_hv_entry in real mode.
@@ -686,6 +687,8 @@ BEGIN_FTR_SECTION
std r6, STACK_SLOT_DAWR0(r1)
std r7, STACK_SLOT_DAWRX0(r1)
std r8, STACK_SLOT_IAMR(r1)
+ mfspr r5, SPRN_FSCR
+ std r5, STACK_SLOT_FSCR(r1)
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
BEGIN_FTR_SECTION
mfspr r6, SPRN_DAWR1
@@ -1663,6 +1666,10 @@ FTR_SECTION_ELSE
ld r7, STACK_SLOT_HFSCR(r1)
mtspr SPRN_HFSCR, r7
ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
+BEGIN_FTR_SECTION
+ ld r5, STACK_SLOT_FSCR(r1)
+ mtspr SPRN_FSCR, r5
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
/*
* Restore various registers to 0, where non-zero values
* set by the guest could disrupt the host.
--
2.23.0
