From a5b0ccb0b5d080c0decb4c9208d9bb6072defa50 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Thu, 13 Mar 2014 20:02:02 +1100 Subject: [PATCH 1/2] KVM: PPC: Book3S HV: Remove bogus duplicate code Commit 7b490411c37f ("KVM: PPC: Book3S HV: Add new state for transactional memory") incorrectly added some duplicate code to the guest exit path because I didn't manage to clean up after a rebase correctly. This removes the extraneous material. The presence of this extraneous code causes host crashes whenever a guest is run. Signed-off-by: Paul Mackerras Signed-off-by: Paolo Bonzini --- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 67 ------------------------- 1 file changed, 67 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index e66d4ec04d95..781e6bf69afb 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -1504,73 +1504,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) 1: addi r8,r8,16 .endr - /* Save DEC */ - mfspr r5,SPRN_DEC - mftb r6 - extsw r5,r5 - add r5,r5,r6 - std r5,VCPU_DEC_EXPIRES(r9) - -BEGIN_FTR_SECTION - b 8f -END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S) - /* Turn on TM so we can access TFHAR/TFIAR/TEXASR */ - mfmsr r8 - li r0, 1 - rldimi r8, r0, MSR_TM_LG, 63-MSR_TM_LG - mtmsrd r8 - - /* Save POWER8-specific registers */ - mfspr r5, SPRN_IAMR - mfspr r6, SPRN_PSPB - mfspr r7, SPRN_FSCR - std r5, VCPU_IAMR(r9) - stw r6, VCPU_PSPB(r9) - std r7, VCPU_FSCR(r9) - mfspr r5, SPRN_IC - mfspr r6, SPRN_VTB - mfspr r7, SPRN_TAR - std r5, VCPU_IC(r9) - std r6, VCPU_VTB(r9) - std r7, VCPU_TAR(r9) -#ifdef CONFIG_PPC_TRANSACTIONAL_MEM - mfspr r5, SPRN_TFHAR - mfspr r6, SPRN_TFIAR - mfspr r7, SPRN_TEXASR - std r5, VCPU_TFHAR(r9) - std r6, VCPU_TFIAR(r9) - std r7, VCPU_TEXASR(r9) -#endif - mfspr r8, SPRN_EBBHR - std r8, VCPU_EBBHR(r9) - mfspr r5, SPRN_EBBRR - mfspr r6, SPRN_BESCR - mfspr r7, SPRN_CSIGR - mfspr r8, SPRN_TACR - std r5, VCPU_EBBRR(r9) - std r6, VCPU_BESCR(r9) - std r7, VCPU_CSIGR(r9) - std r8, VCPU_TACR(r9) - mfspr r5, SPRN_TCSCR - mfspr r6, SPRN_ACOP - mfspr r7, SPRN_PID - mfspr r8, SPRN_WORT - std r5, VCPU_TCSCR(r9) - std r6, VCPU_ACOP(r9) - stw r7, VCPU_GUEST_PID(r9) - std r8, VCPU_WORT(r9) -8: - - /* Save and reset AMR and UAMOR before turning on the MMU */ -BEGIN_FTR_SECTION - mfspr r5,SPRN_AMR - mfspr r6,SPRN_UAMOR - std r5,VCPU_AMR(r9) - std r6,VCPU_UAMOR(r9) - li r6,0 - mtspr SPRN_AMR,r6 -END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206) - /* Unset guest mode */ li r0, KVM_GUEST_MODE_NONE stb r0, HSTATE_IN_GUEST(r13) From e724f080f5dd03881bc6d378750c37f7374cae7e Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Thu, 13 Mar 2014 20:02:48 +1100 Subject: [PATCH 2/2] KVM: PPC: Book3S HV: Fix register usage when loading/saving VRSAVE Commit 595e4f7e697e ("KVM: PPC: Book3S HV: Use load/store_fp_state functions in HV guest entry/exit") changed the register usage in kvmppc_save_fp() and kvmppc_load_fp() but omitted changing the instructions that load and save VRSAVE. The result is that the VRSAVE value was loaded from a constant address, and saved to a location past the end of the vcpu struct, causing host kernel memory corruption and various kinds of host kernel crashes. This fixes the problem by using register r31, which contains the vcpu pointer, instead of r3 and r4. Signed-off-by: Paul Mackerras Signed-off-by: Paolo Bonzini --- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index 781e6bf69afb..818dce344e82 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -2136,7 +2136,7 @@ BEGIN_FTR_SECTION END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) #endif mfspr r6,SPRN_VRSAVE - stw r6,VCPU_VRSAVE(r3) + stw r6,VCPU_VRSAVE(r31) mtlr r30 mtmsrd r5 isync @@ -2173,7 +2173,7 @@ BEGIN_FTR_SECTION bl .load_vr_state END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) #endif - lwz r7,VCPU_VRSAVE(r4) + lwz r7,VCPU_VRSAVE(r31) mtspr SPRN_VRSAVE,r7 mtlr r30 mr r4,r31