diff options
| author | Paul Mackerras <paulus@ozlabs.org> | 2023-03-08 17:36:11 +1100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2023-04-03 15:45:59 +1000 |
| commit | a3800ef9c48c4497dafe5ede1b65d91d9ef9cf1e (patch) | |
| tree | ba1c7ea92cc4ca0156fb5f00fe6a8fbe946ca658 /arch/powerpc/kvm | |
| parent | 953e37397fb61be61f095d36972188bac5235021 (diff) | |
KVM: PPC: Enable prefixed instructions for HV KVM and disable for PR KVM
Now that we can read prefixed instructions from a HV KVM guest and
emulate prefixed load/store instructions to emulated MMIO locations,
we can add HFSCR_PREFIXED into the set of bits that are set in the
HFSCR for a HV KVM guest on POWER10, allowing the guest to use
prefixed instructions.
PR KVM has not yet been extended to handle prefixed instructions in
all situations where we might need to emulate them, so prevent the
guest from enabling prefixed instructions in the FSCR for now.
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/ZAgs25dCmLrVkBdU@cleo
Diffstat (limited to 'arch/powerpc/kvm')
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv.c | 9 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_pr.c | 2 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_rmhandlers.S | 1 |
3 files changed, 10 insertions, 2 deletions
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 283b9bcb014c..c973bf556fb3 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -2930,13 +2930,18 @@ static int kvmppc_core_vcpu_create_hv(struct kvm_vcpu *vcpu) /* * 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 + * This value is only used on POWER9 and later. + * On >= POWER9, we want to virtualize the doorbell facility, so we * don't set the HFSCR_MSGP bit, and that causes those instructions * to trap and then we emulate them. */ vcpu->arch.hfscr = HFSCR_TAR | HFSCR_EBB | HFSCR_PM | HFSCR_BHRB | HFSCR_DSCR | HFSCR_VECVSX | HFSCR_FP; + + /* On POWER10 and later, allow prefixed instructions */ + if (cpu_has_feature(CPU_FTR_ARCH_31)) + vcpu->arch.hfscr |= HFSCR_PREFIX; + if (cpu_has_feature(CPU_FTR_HVMODE)) { vcpu->arch.hfscr &= mfspr(SPRN_HFSCR); #ifdef CONFIG_PPC_TRANSACTIONAL_MEM diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index 556d90e018b3..da0e888e2521 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -1044,6 +1044,8 @@ void kvmppc_set_fscr(struct kvm_vcpu *vcpu, u64 fscr) { if (fscr & FSCR_SCV) fscr &= ~FSCR_SCV; /* SCV must not be enabled */ + /* Prohibit prefixed instructions for now */ + fscr &= ~FSCR_PREFIX; if ((vcpu->arch.fscr & FSCR_TAR) && !(fscr & FSCR_TAR)) { /* TAR got dropped, drop it in shadow too */ kvmppc_giveup_fac(vcpu, FSCR_TAR_LG); diff --git a/arch/powerpc/kvm/book3s_rmhandlers.S b/arch/powerpc/kvm/book3s_rmhandlers.S index 03886ca24498..0a557ffca9fe 100644 --- a/arch/powerpc/kvm/book3s_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_rmhandlers.S @@ -123,6 +123,7 @@ INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_ALTIVEC kvmppc_handler_skip_ins: /* Patch the IP to the next instruction */ + /* Note that prefixed instructions are disabled in PR KVM for now */ mfsrr0 r12 addi r12, r12, 4 mtsrr0 r12 |