path: root/arch/powerpc
diff options
authorNicholas Piggin <>2021-05-26 22:58:51 +1000
committerMichael Ellerman <>2021-05-28 22:54:27 +1000
commit1438709e6328925ef496dafd467dbd0353137434 (patch)
tree11b23d8a15f2ba940fa8d0923377f6cb8f4ff220 /arch/powerpc
parent5362a4b6ee6136018558ef6b2c4701aa15ebc602 (diff)
KVM: PPC: Book3S HV: Save host FSCR in the P7/8 path
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. Now both the p9 and the p7/8 paths now save and restore their FSCR, it no longer needs to be restored at the end of kvmppc_vcpu_run_hv Fixes: b005255e12a3 ("KVM: PPC: Book3S HV: Context-switch new POWER8 SPRs") Cc: # v3.14+ Signed-off-by: Nicholas Piggin <> Reviewed-by: Fabiano Rosas <> Signed-off-by: Michael Ellerman <> Link:
Diffstat (limited to 'arch/powerpc')
2 files changed, 7 insertions, 1 deletions
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 28a80d240b76..13728495ac66 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4455,7 +4455,6 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
mtspr(SPRN_EBBRR, ebb_regs[1]);
mtspr(SPRN_BESCR, ebb_regs[2]);
mtspr(SPRN_TAR, user_tar);
- mtspr(SPRN_FSCR, current->thread.fscr);
mtspr(SPRN_VRSAVE, user_vrsave);
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 5e634db4809b..004f0d4e665f 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -59,6 +59,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
#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 */
@@ -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)
mfspr r6, SPRN_DAWR1
@@ -1663,6 +1666,10 @@ FTR_SECTION_ELSE
mtspr SPRN_HFSCR, r7
+ ld r5, STACK_SLOT_FSCR(r1)
+ mtspr SPRN_FSCR, r5
* Restore various registers to 0, where non-zero values
* set by the guest could disrupt the host.