From 3587d5348ced089666c51411bd9d771fb0b072cf Mon Sep 17 00:00:00 2001 From: Alexander Graf Date: Fri, 19 Feb 2010 11:00:30 +0100 Subject: [PATCH] KVM: PPC: Teach MMIO Signedness The guest I was trying to get to run uses the LHA and LHAU instructions. Those instructions basically do a load, but also sign extend the result. Since we need to fill our registers by hand when doing MMIO, we also need to sign extend manually. This patch implements sign extended MMIO and the LHA(U) instructions. Signed-off-by: Alexander Graf Signed-off-by: Avi Kivity --- arch/powerpc/include/asm/kvm_host.h | 1 + arch/powerpc/include/asm/kvm_ppc.h | 3 +++ arch/powerpc/kvm/emulate.c | 14 ++++++++++++++ arch/powerpc/kvm/powerpc.c | 29 +++++++++++++++++++++++++++++ 4 files changed, 47 insertions(+) diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index fb87dcf418b..119deb4750d 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -270,6 +270,7 @@ struct kvm_vcpu_arch { u8 io_gpr; /* GPR used as IO source/target */ u8 mmio_is_bigendian; + u8 mmio_sign_extend; u8 dcr_needed; u8 dcr_is_write; diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h index c011170f572..a288dd2fbb2 100644 --- a/arch/powerpc/include/asm/kvm_ppc.h +++ b/arch/powerpc/include/asm/kvm_ppc.h @@ -48,6 +48,9 @@ extern void kvmppc_dump_vcpu(struct kvm_vcpu *vcpu); extern int kvmppc_handle_load(struct kvm_run *run, struct kvm_vcpu *vcpu, unsigned int rt, unsigned int bytes, int is_bigendian); +extern int kvmppc_handle_loads(struct kvm_run *run, struct kvm_vcpu *vcpu, + unsigned int rt, unsigned int bytes, + int is_bigendian); extern int kvmppc_handle_store(struct kvm_run *run, struct kvm_vcpu *vcpu, u64 val, unsigned int bytes, int is_bigendian); diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c index cb72a65f4ec..11789dd33a1 100644 --- a/arch/powerpc/kvm/emulate.c +++ b/arch/powerpc/kvm/emulate.c @@ -62,6 +62,8 @@ #define OP_STBU 39 #define OP_LHZ 40 #define OP_LHZU 41 +#define OP_LHA 42 +#define OP_LHAU 43 #define OP_STH 44 #define OP_STHU 45 @@ -450,6 +452,18 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu) kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed); break; + case OP_LHA: + rt = get_rt(inst); + emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1); + break; + + case OP_LHAU: + ra = get_ra(inst); + rt = get_rt(inst); + emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1); + kvmppc_set_gpr(vcpu, ra, vcpu->arch.paddr_accessed); + break; + case OP_STH: rs = get_rs(inst); emulated = kvmppc_handle_store(run, vcpu, diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index b7858b1e15e..1266ed02b47 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -301,6 +301,22 @@ static void kvmppc_complete_mmio_load(struct kvm_vcpu *vcpu, } } + if (vcpu->arch.mmio_sign_extend) { + switch (run->mmio.len) { +#ifdef CONFIG_PPC64 + case 4: + gpr = (s64)(s32)gpr; + break; +#endif + case 2: + gpr = (s64)(s16)gpr; + break; + case 1: + gpr = (s64)(s8)gpr; + break; + } + } + kvmppc_set_gpr(vcpu, vcpu->arch.io_gpr, gpr); switch (vcpu->arch.io_gpr & KVM_REG_EXT_MASK) { @@ -338,10 +354,23 @@ int kvmppc_handle_load(struct kvm_run *run, struct kvm_vcpu *vcpu, vcpu->arch.mmio_is_bigendian = is_bigendian; vcpu->mmio_needed = 1; vcpu->mmio_is_write = 0; + vcpu->arch.mmio_sign_extend = 0; return EMULATE_DO_MMIO; } +/* Same as above, but sign extends */ +int kvmppc_handle_loads(struct kvm_run *run, struct kvm_vcpu *vcpu, + unsigned int rt, unsigned int bytes, int is_bigendian) +{ + int r; + + r = kvmppc_handle_load(run, vcpu, rt, bytes, is_bigendian); + vcpu->arch.mmio_sign_extend = 1; + + return r; +} + int kvmppc_handle_store(struct kvm_run *run, struct kvm_vcpu *vcpu, u64 val, unsigned int bytes, int is_bigendian) { -- 2.39.5