diff options
| author | Paul Mackerras <paulus@samba.org> | 2013-02-04 18:10:51 (GMT) |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2013-02-15 05:54:33 (GMT) |
| commit | 0acb91112a148fbb31678e66839ef757f3be3aa4 (patch) | |
| tree | 9516f90d03a55bc07f8b13b67d497dea8062430c /arch/powerpc/kvm | |
| parent | 1707dd161349e6c54170c88d94fed012e3d224e3 (diff) | |
| download | linux-fsl-qoriq-0acb91112a148fbb31678e66839ef757f3be3aa4.tar.xz | |
powerpc/kvm/book3s_hv: Preserve guest CFAR register value
The CFAR (Come-From Address Register) is a useful debugging aid that
exists on POWER7 processors. Currently HV KVM doesn't save or restore
the CFAR register for guest vcpus, making the CFAR of limited use in
guests.
This adds the necessary code to capture the CFAR value saved in the
early exception entry code (it has to be saved before any branch is
executed), save it in the vcpu.arch struct, and restore it on entry
to the guest.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kvm')
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_rmhandlers.S | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index 10b6c35..e33d11f 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -539,6 +539,11 @@ fast_guest_return: /* Enter guest */ +BEGIN_FTR_SECTION + ld r5, VCPU_CFAR(r4) + mtspr SPRN_CFAR, r5 +END_FTR_SECTION_IFSET(CPU_FTR_CFAR) + ld r5, VCPU_LR(r4) lwz r6, VCPU_CR(r4) mtlr r5 @@ -604,6 +609,10 @@ kvmppc_interrupt: lwz r4, HSTATE_SCRATCH1(r13) std r3, VCPU_GPR(R12)(r9) stw r4, VCPU_CR(r9) +BEGIN_FTR_SECTION + ld r3, HSTATE_CFAR(r13) + std r3, VCPU_CFAR(r9) +END_FTR_SECTION_IFSET(CPU_FTR_CFAR) /* Restore R1/R2 so we can handle faults */ ld r1, HSTATE_HOST_R1(r13) |