On PPC, CR2-CR4 are nonvolatile, thus have to be saved across function calls. We didn't respect that for any architecture until Paul spotted it in his patch for Book3S-HV. This patch saves/restores CR for all KVM capable PPC hosts. Signed-off-by: Alexander Graf <agraf@xxxxxxx> --- v1 -> v2: - optimize bookehv path --- arch/powerpc/kvm/book3s_interrupts.S | 7 +++++++ arch/powerpc/kvm/booke_interrupts.S | 7 ++++++- arch/powerpc/kvm/bookehv_interrupts.S | 8 +++++++- 3 files changed, 20 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kvm/book3s_interrupts.S b/arch/powerpc/kvm/book3s_interrupts.S index 0a8515a..3e35383 100644 --- a/arch/powerpc/kvm/book3s_interrupts.S +++ b/arch/powerpc/kvm/book3s_interrupts.S @@ -84,6 +84,10 @@ kvm_start_entry: /* Save non-volatile registers (r14 - r31) */ SAVE_NVGPRS(r1) + /* Save CR */ + mfcr r14 + stw r14, _CCR(r1) + /* Save LR */ PPC_STL r0, _LINK(r1) @@ -165,6 +169,9 @@ kvm_exit_loop: PPC_LL r4, _LINK(r1) mtlr r4 + lwz r14, _CCR(r1) + mtcr r14 + /* Restore non-volatile host registers (r14 - r31) */ REST_NVGPRS(r1) diff --git a/arch/powerpc/kvm/booke_interrupts.S b/arch/powerpc/kvm/booke_interrupts.S index 10d8ef6..c8c4b87 100644 --- a/arch/powerpc/kvm/booke_interrupts.S +++ b/arch/powerpc/kvm/booke_interrupts.S @@ -34,7 +34,8 @@ /* r2 is special: it holds 'current', and it made nonvolatile in the * kernel with the -ffixed-r2 gcc option. */ #define HOST_R2 12 -#define HOST_NV_GPRS 16 +#define HOST_CR 16 +#define HOST_NV_GPRS 20 #define HOST_NV_GPR(n) (HOST_NV_GPRS + ((n - 14) * 4)) #define HOST_MIN_STACK_SIZE (HOST_NV_GPR(31) + 4) #define HOST_STACK_SIZE (((HOST_MIN_STACK_SIZE + 15) / 16) * 16) /* Align. */ @@ -296,8 +297,10 @@ heavyweight_exit: /* Return to kvm_vcpu_run(). */ lwz r4, HOST_STACK_LR(r1) + lwz r5, HOST_CR(r1) addi r1, r1, HOST_STACK_SIZE mtlr r4 + mtcr r5 /* r3 still contains the return code from kvmppc_handle_exit(). */ blr @@ -314,6 +317,8 @@ _GLOBAL(__kvmppc_vcpu_run) stw r3, HOST_RUN(r1) mflr r3 stw r3, HOST_STACK_LR(r1) + mfcr r5 + stw r5, HOST_CR(r1) /* Save host non-volatile register state to stack. */ stw r14, HOST_NV_GPR(r14)(r1) diff --git a/arch/powerpc/kvm/bookehv_interrupts.S b/arch/powerpc/kvm/bookehv_interrupts.S index 63fc5f0..b71ddaf 100644 --- a/arch/powerpc/kvm/bookehv_interrupts.S +++ b/arch/powerpc/kvm/bookehv_interrupts.S @@ -49,7 +49,8 @@ * kernel with the -ffixed-r2 gcc option. */ #define HOST_R2 (3 * LONGBYTES) -#define HOST_NV_GPRS (4 * LONGBYTES) +#define HOST_CR (4 * LONGBYTES) +#define HOST_NV_GPRS (5 * LONGBYTES) #define HOST_NV_GPR(n) (HOST_NV_GPRS + ((n - 14) * LONGBYTES)) #define HOST_MIN_STACK_SIZE (HOST_NV_GPR(31) + LONGBYTES) #define HOST_STACK_SIZE ((HOST_MIN_STACK_SIZE + 15) & ~15) /* Align. */ @@ -396,6 +397,7 @@ skip_nv_load: heavyweight_exit: /* Not returning to guest. */ PPC_LL r5, HOST_STACK_LR(r1) + lwz r6, HOST_CR(r1) /* * We already saved guest volatile register state; now save the @@ -442,6 +444,7 @@ heavyweight_exit: /* Return to kvm_vcpu_run(). */ mtlr r5 + mtcr r6 addi r1, r1, HOST_STACK_SIZE /* r3 still contains the return code from kvmppc_handle_exit(). */ blr @@ -457,8 +460,11 @@ _GLOBAL(__kvmppc_vcpu_run) /* Save host state to stack. */ PPC_STL r3, HOST_RUN(r1) mflr r3 + mfcr r5 PPC_STL r3, HOST_STACK_LR(r1) + stw r5, HOST_CR(r1) + /* Save host non-volatile register state to stack. */ PPC_STL r14, HOST_NV_GPR(r14)(r1) PPC_STL r15, HOST_NV_GPR(r15)(r1) -- 1.6.0.2 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
