When running as a nested hypervisor, this avoids reading hypervisor
privileged registers (specifically HFSCR, LPIDR and LPCR) at startup;
instead reasonable default values are used. This also avoids writing
LPIDR in the single-vcpu entry/exit path.
Also, this removes the check for CPU_FTR_HVMODE in kvmppc_mmu_hv_init()
since its only caller already checks this.
Reviewed-by: David Gibson <da...@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <pau...@ozlabs.org>
---
arch/powerpc/kvm/book3s_64_mmu_hv.c | 7 +++----
arch/powerpc/kvm/book3s_hv.c | 33 +++++++++++++++++++++------------
2 files changed, 24 insertions(+), 16 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c
b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index 68e14af..c615617 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -268,14 +268,13 @@ int kvmppc_mmu_hv_init(void)
{
unsigned long host_lpid, rsvd_lpid;
- if (!cpu_has_feature(CPU_FTR_HVMODE))
- return -EINVAL;
-
if (!mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE))
return -EINVAL;
/* POWER7 has 10-bit LPIDs (12-bit in POWER8) */
- host_lpid = mfspr(SPRN_LPID);
+ host_lpid = 0;
+ if (cpu_has_feature(CPU_FTR_HVMODE))
+ host_lpid = mfspr(SPRN_LPID);
rsvd_lpid = LPID_RSVD;
kvmppc_init_lpid(rsvd_lpid + 1);
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 24a6683..b8f14ea 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -2174,15 +2174,18 @@ static struct kvm_vcpu
*kvmppc_core_vcpu_create_hv(struct kvm *kvm,
* Set the default HFSCR for the guest from the host value.
* This value is only used on POWER9.
* On POWER9, we want to virtualize the doorbell facility, so we
- * turn off the HFSCR bit, which causes those instructions to trap.
+ * don't set the HFSCR_MSGP bit, and that causes those instructions
+ * to trap and then we emulate them.
*/
- vcpu->arch.hfscr = mfspr(SPRN_HFSCR);
- if (cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
+ vcpu->arch.hfscr = HFSCR_TAR | HFSCR_EBB | HFSCR_PM | HFSCR_BHRB |
+ HFSCR_DSCR | HFSCR_VECVSX | HFSCR_FP;
+ if (cpu_has_feature(CPU_FTR_HVMODE)) {
+ vcpu->arch.hfscr &= mfspr(SPRN_HFSCR);
+ if (cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
+ vcpu->arch.hfscr |= HFSCR_TM;
+ }
+ if (cpu_has_feature(CPU_FTR_TM_COMP))
vcpu->arch.hfscr |= HFSCR_TM;
- else if (!cpu_has_feature(CPU_FTR_TM_COMP))
- vcpu->arch.hfscr &= ~HFSCR_TM;
- if (cpu_has_feature(CPU_FTR_ARCH_300))
- vcpu->arch.hfscr &= ~HFSCR_MSGP;
kvmppc_mmu_book3s_hv_init(vcpu);
@@ -4002,8 +4005,10 @@ int kvmhv_run_single_vcpu(struct kvm_run *kvm_run,
srcu_read_unlock(&kvm->srcu, srcu_idx);
- mtspr(SPRN_LPID, kvm->arch.host_lpid);
- isync();
+ if (cpu_has_feature(CPU_FTR_HVMODE)) {
+ mtspr(SPRN_LPID, kvm->arch.host_lpid);
+ isync();
+ }
trace_hardirqs_off();
set_irq_happened(trap);
@@ -4630,9 +4635,13 @@ static int kvmppc_core_init_vm_hv(struct kvm *kvm)
kvm->arch.host_sdr1 = mfspr(SPRN_SDR1);
/* Init LPCR for virtual RMA mode */
- kvm->arch.host_lpid = mfspr(SPRN_LPID);
- kvm->arch.host_lpcr = lpcr = mfspr(SPRN_LPCR);
- lpcr &= LPCR_PECE | LPCR_LPES;
+ if (cpu_has_feature(CPU_FTR_HVMODE)) {
+ kvm->arch.host_lpid = mfspr(SPRN_LPID);
+ kvm->arch.host_lpcr = lpcr = mfspr(SPRN_LPCR);
+ lpcr &= LPCR_PECE | LPCR_LPES;
+ } else {
+ lpcr = 0;
+ }
lpcr |= (4UL << LPCR_DPFD_SH) | LPCR_HDICE |
LPCR_VPM0 | LPCR_VPM1;
kvm->arch.vrma_slb_v = SLB_VSID_B_1T |
--
2.7.4
