diff options
| author | Scott Wood <scottwood@freescale.com> | 2011-11-09 04:23:30 +0400 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2012-03-05 16:52:26 +0400 |
| commit | b59049720dd95021dfe0d9f4e1fa9458a67cfe29 (patch) | |
| tree | 3b54577e12ba4a84bec409518c6c8f399ebba6e0 /arch/powerpc/kvm/booke_interrupts.S | |
| parent | 940b45ec18cf00046b8b28299d97066a2c43d559 (diff) | |
| download | linux-b59049720dd95021dfe0d9f4e1fa9458a67cfe29.tar.xz | |
KVM: PPC: Paravirtualize SPRG4-7, ESR, PIR, MASn
This allows additional registers to be accessed by the guest
in PR-mode KVM without trapping.
SPRG4-7 are readable from userspace. On booke, KVM will sync
these registers when it enters the guest, so that accesses from
guest userspace will work. The guest kernel, OTOH, must consistently
use either the real registers or the shared area between exits. This
also applies to the already-paravirted SPRG3.
On non-booke, it's not clear to what extent SPRG4-7 are supported
(they're not architected for book3s, but exist on at least some classic
chips). They are copied in the get/set regs ioctls, but I do not see any
non-booke emulation. I also do not see any syncing with real registers
(in PR-mode) including the user-readable SPRG3. This patch should not
make that situation any worse.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/powerpc/kvm/booke_interrupts.S')
| -rw-r--r-- | arch/powerpc/kvm/booke_interrupts.S | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/arch/powerpc/kvm/booke_interrupts.S b/arch/powerpc/kvm/booke_interrupts.S index 42f2fb1f66e9..10d8ef602e5c 100644 --- a/arch/powerpc/kvm/booke_interrupts.S +++ b/arch/powerpc/kvm/booke_interrupts.S @@ -402,19 +402,25 @@ lightweight_exit: /* Save vcpu pointer for the exception handlers. */ mtspr SPRN_SPRG_WVCPU, r4 + lwz r5, VCPU_SHARED(r4) + /* Can't switch the stack pointer until after IVPR is switched, * because host interrupt handlers would get confused. */ lwz r1, VCPU_GPR(r1)(r4) - /* Host interrupt handlers may have clobbered these guest-readable - * SPRGs, so we need to reload them here with the guest's values. */ - lwz r3, VCPU_SPRG4(r4) + /* + * Host interrupt handlers may have clobbered these + * guest-readable SPRGs, or the guest kernel may have + * written directly to the shared area, so we + * need to reload them here with the guest's values. + */ + lwz r3, VCPU_SHARED_SPRG4(r5) mtspr SPRN_SPRG4W, r3 - lwz r3, VCPU_SPRG5(r4) + lwz r3, VCPU_SHARED_SPRG5(r5) mtspr SPRN_SPRG5W, r3 - lwz r3, VCPU_SPRG6(r4) + lwz r3, VCPU_SHARED_SPRG6(r5) mtspr SPRN_SPRG6W, r3 - lwz r3, VCPU_SPRG7(r4) + lwz r3, VCPU_SHARED_SPRG7(r5) mtspr SPRN_SPRG7W, r3 #ifdef CONFIG_KVM_EXIT_TIMING |