We allow priv-mode update of this. The guest value is saved in fscr,
and the value actually used is saved in shadow_fscr. shadow_fscr
only contains values that are allowed by the host. On
facility unavailable interrupt, if the facility is allowed by fscr
but disabled in shadow_fscr we need to emulate the support. Currently
all but EBB is disabled. We still don't support performance monitoring
in PR guest.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/include/asm/kvm_book3s_asm.h | 1 +
arch/powerpc/include/asm/kvm_host.h | 1 +
arch/powerpc/kernel/asm-offsets.c | 2 ++
arch/powerpc/kvm/book3s_emulate.c | 16 ++++++++++++++++
arch/powerpc/kvm/book3s_interrupts.S | 25 ++++++++++++++++++++++---
5 files changed, 42 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_book3s_asm.h b/arch/powerpc/include/asm/kvm_book3s_asm.h
index 192917d2239c..abd42523ad93 100644
--- a/arch/powerpc/include/asm/kvm_book3s_asm.h
+++ b/arch/powerpc/include/asm/kvm_book3s_asm.h
@@ -103,6 +103,7 @@ struct kvmppc_host_state {
#ifdef CONFIG_PPC_BOOK3S_64
u64 cfar;
u64 ppr;
+ u64 host_fscr;
#endif
};
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index e0b13aca98e6..f4be7be14330 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -478,6 +478,7 @@ struct kvm_vcpu_arch {
ulong ppr;
ulong pspb;
ulong fscr;
+ ulong shadow_fscr;
ulong tfhar;
ulong tfiar;
ulong texasr;
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 2c2227da6917..7484676b8f25 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -525,6 +525,7 @@ int main(void)
DEFINE(VCPU_CFAR, offsetof(struct kvm_vcpu, arch.cfar));
DEFINE(VCPU_PPR, offsetof(struct kvm_vcpu, arch.ppr));
DEFINE(VCPU_FSCR, offsetof(struct kvm_vcpu, arch.fscr));
+ DEFINE(VCPU_SHADOW_FSCR, offsetof(struct kvm_vcpu, arch.shadow_fscr));
DEFINE(VCPU_PSPB, offsetof(struct kvm_vcpu, arch.pspb));
DEFINE(VCPU_TFHAR, offsetof(struct kvm_vcpu, arch.tfhar));
DEFINE(VCPU_TFIAR, offsetof(struct kvm_vcpu, arch.tfiar));
@@ -626,6 +627,7 @@ int main(void)
#ifdef CONFIG_PPC_BOOK3S_64
HSTATE_FIELD(HSTATE_CFAR, cfar);
HSTATE_FIELD(HSTATE_PPR, ppr);
+ HSTATE_FIELD(HSTATE_FSCR, host_fscr);
#endif /* CONFIG_PPC_BOOK3S_64 */
#else /* CONFIG_PPC_BOOK3S */
diff --git a/arch/powerpc/kvm/book3s_emulate.c b/arch/powerpc/kvm/book3s_emulate.c
index 7f25adbd2590..60d0b6b745e7 100644
--- a/arch/powerpc/kvm/book3s_emulate.c
+++ b/arch/powerpc/kvm/book3s_emulate.c
@@ -468,6 +468,19 @@ int kvmppc_core_emulate_mtspr_pr(struct kvm_vcpu *vcpu, int sprn, ulong spr_val)
case SPRN_MSSSR0:
case SPRN_DABR:
break;
+ case SPRN_FSCR:
+ {
+ ulong host_fscr = mfspr(SPRN_FSCR);
+ /*
+ * We disable FSCR_EBB for pr guest. TAR and DSCR are always
+ * enabled.
+ */
+ if (spr_val & ~(FSCR_TAR|FSCR_DSCR|FSCR_EBB))
+ pr_info("KVM: invalud FSCR value 0x%lx", spr_val);
+ vcpu->arch.fscr = spr_val & (FSCR_TAR|FSCR_DSCR);
+ vcpu->arch.shadow_fscr = vcpu->arch.fscr & host_fscr;
+ break;
+ }
unprivileged:
default:
printk(KERN_INFO "KVM: invalid SPR write: %d\n", sprn);
@@ -591,6 +604,9 @@ int kvmppc_core_emulate_mfspr_pr(struct kvm_vcpu *vcpu, int sprn, ulong *spr_val
*/
*spr_val = 0;
break;
+ case SPRN_FSCR:
+ *spr_val = vcpu->arch.fscr;
+ break;
default:
unprivileged:
printk(KERN_INFO "KVM: invalid SPR read: %d\n", sprn);
diff --git a/arch/powerpc/kvm/book3s_interrupts.S b/arch/powerpc/kvm/book3s_interrupts.S
index f779450cb07c..fcbdf4817301 100644
--- a/arch/powerpc/kvm/book3s_interrupts.S
+++ b/arch/powerpc/kvm/book3s_interrupts.S
@@ -107,6 +107,14 @@ kvm_start_lightweight:
ld r3, VCPU_SHARED(r4)
ld r3, VCPU_SHARED_SPRG3(r3)
mtspr SPRN_SPRG3, r3
+
+BEGIN_FTR_SECTION
+ mfspr r3,SPRN_FSCR
+ PPC_STL r3, HSTATE_FSCR(r13)
+
+ PPC_LL r3, VCPU_SHADOW_FSCR(r4)
+ mtspr SPRN_FSCR, r3
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
#endif /* CONFIG_PPC_BOOK3S_64 */
PPC_LL r4, VCPU_SHADOW_MSR(r4) /* get shadow_msr */
@@ -148,6 +156,9 @@ kvm_start_lightweight:
bl FUNC(kvmppc_copy_from_svcpu)
nop
+ /* R7 = vcpu */
+ PPC_LL r7, GPR4(r1)
+
#ifdef CONFIG_PPC_BOOK3S_64
/*
* Reload kernel SPRG3 value.
@@ -155,10 +166,18 @@ kvm_start_lightweight:
*/
ld r3, PACA_SPRG3(r13)
mtspr SPRN_SPRG3, r3
-#endif /* CONFIG_PPC_BOOK3S_64 */
+BEGIN_FTR_SECTION
+ /*
+ * Save the current fscr in shadow fscr
+ */
+ mfspr r3,SPRN_FSCR
+ PPC_STL r3, VCPU_SHADOW_FSCR(r7)
- /* R7 = vcpu */
- PPC_LL r7, GPR4(r1)
+ PPC_LL r3, HSTATE_FSCR(r13)
+ mtspr SPRN_FSCR, r3
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
+
+#endif /* CONFIG_PPC_BOOK3S_64 */
PPC_STL r14, VCPU_GPR(R14)(r7)
PPC_STL r15, VCPU_GPR(R15)(r7)
--
1.8.5.3
--
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