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authorAlexander Graf <agraf@suse.de>2012-03-05 16:00:28 +0100
committerPaul Mackerras <paulus@samba.org>2012-04-03 08:42:34 +0200
commite1f8acf8380abfd52aefbfa524e74af5ce0c8492 (patch)
tree39f2637c1a941185003e9e270bf0b4580acde029 /arch/powerpc/kvm
parentKVM: PPC: Book3S HV: Save and restore CR in __kvmppc_vcore_entry (diff)
downloadlinux-e1f8acf8380abfd52aefbfa524e74af5ce0c8492.tar.xz
linux-e1f8acf8380abfd52aefbfa524e74af5ce0c8492.zip
KVM: PPC: Save/Restore CR over vcpu_run
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@suse.de> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/kvm')
-rw-r--r--arch/powerpc/kvm/book3s_interrupts.S7
-rw-r--r--arch/powerpc/kvm/booke_interrupts.S7
2 files changed, 13 insertions, 1 deletions
diff --git a/arch/powerpc/kvm/book3s_interrupts.S b/arch/powerpc/kvm/book3s_interrupts.S
index 0a8515a5c042..3e35383bdb21 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 10d8ef602e5c..c8c4b878795a 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)