From patchwork Fri Feb 3 10:53:21 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [1/4] KVM: PPC: Book3S HV: Save and restore CR in __kvmppc_vcore_entry Date: Fri, 03 Feb 2012 00:53:21 -0000 From: Paul Mackerras X-Patchwork-Id: 139342 Message-Id: <20120203105320.GC30287@bloggs.ozlabs.ibm.com> To: Alexander Graf Cc: kvm-ppc@vger.kernel.org The ABI specifies that CR fields CR2--CR4 are nonvolatile across function calls. Currently __kvmppc_vcore_entry doesn't save and restore the CR, leading to CR2--CR4 getting corrupted with guest values, possibly leading to incorrect behaviour in its caller. This adds instructions to save and restore CR at the points where we save and restore the nonvolatile GPRs. Signed-off-by: Paul Mackerras --- arch/powerpc/kvm/book3s_hv_interrupts.S | 8 ++++++-- 1 files changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv_interrupts.S b/arch/powerpc/kvm/book3s_hv_interrupts.S index 3f7b674..d3fb4df 100644 --- a/arch/powerpc/kvm/book3s_hv_interrupts.S +++ b/arch/powerpc/kvm/book3s_hv_interrupts.S @@ -46,8 +46,10 @@ _GLOBAL(__kvmppc_vcore_entry) /* Save host state to the stack */ stdu r1, -SWITCH_FRAME_SIZE(r1) - /* Save non-volatile registers (r14 - r31) */ + /* Save non-volatile registers (r14 - r31) and CR */ SAVE_NVGPRS(r1) + mfcr r3 + std r3, _CCR(r1) /* Save host DSCR */ BEGIN_FTR_SECTION @@ -157,8 +159,10 @@ kvmppc_handler_highmem: * R13 = PACA */ - /* Restore non-volatile host registers (r14 - r31) */ + /* Restore non-volatile host registers (r14 - r31) and CR */ REST_NVGPRS(r1) + ld r4, _CCR(r1) + mtcr r4 addi r1, r1, SWITCH_FRAME_SIZE ld r0, PPC_LR_STKOFF(r1)