KVM: PPC: Book3S: Add MMIO emulation for VMX instructions

This patch provides the MMIO load/store vector indexed
X-Form emulation.

Instructions implemented:
lvx: the quadword in storage addressed by the result of EA &
0xffff_ffff_ffff_fff0 is loaded into VRT.

stvx: the contents of VRS are stored into the quadword in storage
addressed by the result of EA & 0xffff_ffff_ffff_fff0.

Reported-by: Gopesh Kumar Chaudhary <gopchaud@in.ibm.com>
Reported-by: Balamuruhan S <bala24@linux.vnet.ibm.com>
Signed-off-by: Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

1 files changed, 150 insertions, 0 deletions

diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index cf86aeb43fcf..47c7a302fd03 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -924,6 +924,34 @@ static inline void kvmppc_set_vsr_word(struct kvm_vcpu *vcpu,
 }
 #endif /* CONFIG_VSX */
 
+#ifdef CONFIG_ALTIVEC
+static inline void kvmppc_set_vmx_dword(struct kvm_vcpu *vcpu,
+		u64 gpr)
+{
+	int index = vcpu->arch.io_gpr & KVM_MMIO_REG_MASK;
+	u32 hi, lo;
+	u32 di;
+
+#ifdef __BIG_ENDIAN
+	hi = gpr >> 32;
+	lo = gpr & 0xffffffff;
+#else
+	lo = gpr >> 32;
+	hi = gpr & 0xffffffff;
+#endif
+
+	di = 2 - vcpu->arch.mmio_vmx_copy_nums;		/* doubleword index */
+	if (di > 1)
+		return;
+
+	if (vcpu->arch.mmio_host_swabbed)
+		di = 1 - di;
+
+	VCPU_VSX_VR(vcpu, index).u[di * 2] = hi;
+	VCPU_VSX_VR(vcpu, index).u[di * 2 + 1] = lo;
+}
+#endif /* CONFIG_ALTIVEC */
+
 #ifdef CONFIG_PPC_FPU
 static inline u64 sp_to_dp(u32 fprs)
 {
@@ -1027,6 +1055,11 @@ static void kvmppc_complete_mmio_load(struct kvm_vcpu *vcpu,
 			kvmppc_set_vsr_dword_dump(vcpu, gpr);
 		break;
 #endif
+#ifdef CONFIG_ALTIVEC
+	case KVM_MMIO_REG_VMX:
+		kvmppc_set_vmx_dword(vcpu, gpr);
+		break;
+#endif
 	default:
 		BUG();
 	}
@@ -1302,6 +1335,111 @@ static int kvmppc_emulate_mmio_vsx_loadstore(struct kvm_vcpu *vcpu,
 }
 #endif /* CONFIG_VSX */
 
+#ifdef CONFIG_ALTIVEC
+/* handle quadword load access in two halves */
+int kvmppc_handle_load128_by2x64(struct kvm_run *run, struct kvm_vcpu *vcpu,
+		unsigned int rt, int is_default_endian)
+{
+	enum emulation_result emulated;
+
+	while (vcpu->arch.mmio_vmx_copy_nums) {
+		emulated = __kvmppc_handle_load(run, vcpu, rt, 8,
+				is_default_endian, 0);
+
+		if (emulated != EMULATE_DONE)
+			break;
+
+		vcpu->arch.paddr_accessed += run->mmio.len;
+		vcpu->arch.mmio_vmx_copy_nums--;
+	}
+
+	return emulated;
+}
+
+static inline int kvmppc_get_vmx_data(struct kvm_vcpu *vcpu, int rs, u64 *val)
+{
+	vector128 vrs = VCPU_VSX_VR(vcpu, rs);
+	u32 di;
+	u64 w0, w1;
+
+	di = 2 - vcpu->arch.mmio_vmx_copy_nums;		/* doubleword index */
+	if (di > 1)
+		return -1;
+
+	if (vcpu->arch.mmio_host_swabbed)
+		di = 1 - di;
+
+	w0 = vrs.u[di * 2];
+	w1 = vrs.u[di * 2 + 1];
+
+#ifdef __BIG_ENDIAN
+	*val = (w0 << 32) | w1;
+#else
+	*val = (w1 << 32) | w0;
+#endif
+	return 0;
+}
+
+/* handle quadword store in two halves */
+int kvmppc_handle_store128_by2x64(struct kvm_run *run, struct kvm_vcpu *vcpu,
+		unsigned int rs, int is_default_endian)
+{
+	u64 val = 0;
+	enum emulation_result emulated = EMULATE_DONE;
+
+	vcpu->arch.io_gpr = rs;
+
+	while (vcpu->arch.mmio_vmx_copy_nums) {
+		if (kvmppc_get_vmx_data(vcpu, rs, &val) == -1)
+			return EMULATE_FAIL;
+
+		emulated = kvmppc_handle_store(run, vcpu, val, 8,
+				is_default_endian);
+		if (emulated != EMULATE_DONE)
+			break;
+
+		vcpu->arch.paddr_accessed += run->mmio.len;
+		vcpu->arch.mmio_vmx_copy_nums--;
+	}
+
+	return emulated;
+}
+
+static int kvmppc_emulate_mmio_vmx_loadstore(struct kvm_vcpu *vcpu,
+		struct kvm_run *run)
+{
+	enum emulation_result emulated = EMULATE_FAIL;
+	int r;
+
+	vcpu->arch.paddr_accessed += run->mmio.len;
+
+	if (!vcpu->mmio_is_write) {
+		emulated = kvmppc_handle_load128_by2x64(run, vcpu,
+				vcpu->arch.io_gpr, 1);
+	} else {
+		emulated = kvmppc_handle_store128_by2x64(run, vcpu,
+				vcpu->arch.io_gpr, 1);
+	}
+
+	switch (emulated) {
+	case EMULATE_DO_MMIO:
+		run->exit_reason = KVM_EXIT_MMIO;
+		r = RESUME_HOST;
+		break;
+	case EMULATE_FAIL:
+		pr_info("KVM: MMIO emulation failed (VMX repeat)\n");
+		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION;
+		r = RESUME_HOST;
+		break;
+	default:
+		r = RESUME_GUEST;
+		break;
+	}
+	return r;
+}
+#endif /* CONFIG_ALTIVEC */
+
 int kvm_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
 {
 	int r = 0;
@@ -1421,6 +1559,18 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 			}
 		}
 #endif
+#ifdef CONFIG_ALTIVEC
+		if (vcpu->arch.mmio_vmx_copy_nums > 0)
+			vcpu->arch.mmio_vmx_copy_nums--;
+
+		if (vcpu->arch.mmio_vmx_copy_nums > 0) {
+			r = kvmppc_emulate_mmio_vmx_loadstore(vcpu, run);
+			if (r == RESUME_HOST) {
+				vcpu->mmio_needed = 1;
+				return r;
+			}
+		}
+#endif
 	} else if (vcpu->arch.osi_needed) {
 		u64 *gprs = run->osi.gprs;
 		int i;