3.16.42-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Paul Mackerras <[email protected]> commit 0d808df06a44200f52262b6eb72bcb6042f5a7c5 upstream. When switching from/to a guest that has a transaction in progress, we need to save/restore the checkpointed register state. Although XER is part of the CPU state that gets checkpointed, the code that does this saving and restoring doesn't save/restore XER. This fixes it by saving and restoring the XER. To allow userspace to read/write the checkpointed XER value, we also add a new ONE_REG specifier. The visible effect of this bug is that the guest may see its XER value being corrupted when it uses transactions. Fixes: e4e38121507a ("KVM: PPC: Book3S HV: Add transactional memory support") Fixes: 0a8eccefcb34 ("KVM: PPC: Book3S HV: Add missing code for transaction reclaim on guest exit") Signed-off-by: Paul Mackerras <[email protected]> Reviewed-by: Thomas Huth <[email protected]> Signed-off-by: Paul Mackerras <[email protected]> [bwh: Backported to 3.16: adjust context, spacing] Signed-off-by: Ben Hutchings <[email protected]> --- Documentation/virtual/kvm/api.txt | 1 + arch/powerpc/include/asm/kvm_host.h | 1 + arch/powerpc/include/uapi/asm/kvm.h | 1 + arch/powerpc/kernel/asm-offsets.c | 1 + arch/powerpc/kvm/book3s_hv.c | 6 ++++++ arch/powerpc/kvm/book3s_hv_rmhandlers.S | 4 ++++ 6 files changed, 14 insertions(+) --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -1891,6 +1891,7 @@ registers, find a list below: PPC | KVM_REG_PPC_TM_VSCR | 32 PPC | KVM_REG_PPC_TM_DSCR | 64 PPC | KVM_REG_PPC_TM_TAR | 64 + PPC | KVM_REG_PPC_TM_XER | 64 ARM registers are mapped using the lower 32 bits. The upper 16 of that is the register group type, or coprocessor number: --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -532,6 +532,7 @@ struct kvm_vcpu_arch { u64 tfiar; u32 cr_tm; + u64 xer_tm; u64 lr_tm; u64 ctr_tm; u64 amr_tm; --- a/arch/powerpc/include/uapi/asm/kvm.h +++ b/arch/powerpc/include/uapi/asm/kvm.h @@ -580,6 +580,7 @@ struct kvm_get_htab_header { #define KVM_REG_PPC_TM_VSCR (KVM_REG_PPC_TM | KVM_REG_SIZE_U32 | 0x67) #define KVM_REG_PPC_TM_DSCR (KVM_REG_PPC_TM | KVM_REG_SIZE_U64 | 0x68) #define KVM_REG_PPC_TM_TAR (KVM_REG_PPC_TM | KVM_REG_SIZE_U64 | 0x69) +#define KVM_REG_PPC_TM_XER (KVM_REG_PPC_TM | KVM_REG_SIZE_U64 | 0x6a) /* PPC64 eXternal Interrupt Controller Specification */ #define KVM_DEV_XICS_GRP_SOURCES 1 /* 64-bit source attributes */ --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -572,6 +572,7 @@ int main(void) DEFINE(VCPU_VRS_TM, offsetof(struct kvm_vcpu, arch.vr_tm.vr)); DEFINE(VCPU_VRSAVE_TM, offsetof(struct kvm_vcpu, arch.vrsave_tm)); DEFINE(VCPU_CR_TM, offsetof(struct kvm_vcpu, arch.cr_tm)); + DEFINE(VCPU_XER_TM, offsetof(struct kvm_vcpu, arch.xer_tm)); DEFINE(VCPU_LR_TM, offsetof(struct kvm_vcpu, arch.lr_tm)); DEFINE(VCPU_CTR_TM, offsetof(struct kvm_vcpu, arch.ctr_tm)); DEFINE(VCPU_AMR_TM, offsetof(struct kvm_vcpu, arch.amr_tm)); --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -988,6 +988,9 @@ static int kvmppc_get_one_reg_hv(struct case KVM_REG_PPC_TM_CR: *val = get_reg_val(id, vcpu->arch.cr_tm); break; + case KVM_REG_PPC_TM_XER: + *val = get_reg_val(id, vcpu->arch.xer_tm); + break; case KVM_REG_PPC_TM_LR: *val = get_reg_val(id, vcpu->arch.lr_tm); break; @@ -1201,6 +1204,9 @@ static int kvmppc_set_one_reg_hv(struct case KVM_REG_PPC_TM_CR: vcpu->arch.cr_tm = set_reg_val(id, *val); break; + case KVM_REG_PPC_TM_XER: + vcpu->arch.xer_tm = set_reg_val(id, *val); + break; case KVM_REG_PPC_TM_LR: vcpu->arch.lr_tm = set_reg_val(id, *val); break; --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -2356,11 +2356,13 @@ kvmppc_save_tm: mfctr r7 mfspr r8, SPRN_AMR mfspr r10, SPRN_TAR + mfxer r11 std r5, VCPU_LR_TM(r9) stw r6, VCPU_CR_TM(r9) std r7, VCPU_CTR_TM(r9) std r8, VCPU_AMR_TM(r9) std r10, VCPU_TAR_TM(r9) + std r11, VCPU_XER_TM(r9) /* Restore r12 as trap number. */ lwz r12, VCPU_TRAP(r9) @@ -2453,11 +2455,13 @@ kvmppc_restore_tm: ld r7, VCPU_CTR_TM(r4) ld r8, VCPU_AMR_TM(r4) ld r9, VCPU_TAR_TM(r4) + ld r10, VCPU_XER_TM(r4) mtlr r5 mtcr r6 mtctr r7 mtspr SPRN_AMR, r8 mtspr SPRN_TAR, r9 + mtxer r10 /* * Load up PPR and DSCR values but don't put them in the actual SPRs
