KVM: PPC: Book3S HV: Add infrastructure to support 2nd DAWR

KVM code assumes single DAWR everywhere. Add code to support 2nd DAWR.
DAWR is a hypervisor resource and thus H_SET_MODE hcall is used to set/
unset it. Introduce new case H_SET_MODE_RESOURCE_SET_DAWR1 for 2nd DAWR.
Also, KVM will support 2nd DAWR only if CPU_FTR_DAWR1 is set.

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

Documentation/virt/kvm/api.rst

@@ -2276,6 +2276,8 @@ registers, find a list below:
   PPC     KVM_REG_PPC_PSSCR               64
   PPC     KVM_REG_PPC_DEC_EXPIRY          64
   PPC     KVM_REG_PPC_PTCR                64
+  PPC     KVM_REG_PPC_DAWR1               64
+  PPC     KVM_REG_PPC_DAWRX1              64
   PPC     KVM_REG_PPC_TM_GPR0             64
   ...
   PPC     KVM_REG_PPC_TM_GPR31            64

arch/powerpc/include/asm/hvcall.h

@@ -569,16 +569,22 @@ struct hv_guest_state {
 	u64 pidr;
 	u64 cfar;
 	u64 ppr;
+	/* Version 1 ends here */
+	u64 dawr1;
+	u64 dawrx1;
+	/* Version 2 ends here */
 };
 
 /* Latest version of hv_guest_state structure */
-#define HV_GUEST_STATE_VERSION	1
+#define HV_GUEST_STATE_VERSION	2
 
 static inline int hv_guest_state_size(unsigned int version)
 {
 	switch (version) {
 	case 1:
 		return offsetofend(struct hv_guest_state, ppr);
+	case 2:
+		return offsetofend(struct hv_guest_state, dawrx1);
 	default:
 		return -1;
 	}

arch/powerpc/include/asm/kvm_host.h

@@ -306,6 +306,7 @@ struct kvm_arch {
 	u8 svm_enabled;
 	bool threads_indep;
 	bool nested_enable;
+	bool dawr1_enabled;
 	pgd_t *pgtable;
 	u64 process_table;
 	struct dentry *debugfs_dir;
@@ -585,6 +586,8 @@ struct kvm_vcpu_arch {
 	ulong dabr;
 	ulong dawr0;
 	ulong dawrx0;
+	ulong dawr1;
+	ulong dawrx1;
 	ulong ciabr;
 	ulong cfar;
 	ulong ppr;

arch/powerpc/include/uapi/asm/kvm.h

@@ -644,6 +644,8 @@ struct kvm_ppc_cpu_char {
 #define KVM_REG_PPC_MMCR3	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xc1)
 #define KVM_REG_PPC_SIER2	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xc2)
 #define KVM_REG_PPC_SIER3	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xc3)
+#define KVM_REG_PPC_DAWR1	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xc4)
+#define KVM_REG_PPC_DAWRX1	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xc5)
 
 /* Transactional Memory checkpointed state:
  * This is all GPRs, all VSX regs and a subset of SPRs

arch/powerpc/kernel/asm-offsets.c

@@ -528,6 +528,8 @@ int main(void)
 	OFFSET(VCPU_DABRX, kvm_vcpu, arch.dabrx);
 	OFFSET(VCPU_DAWR0, kvm_vcpu, arch.dawr0);
 	OFFSET(VCPU_DAWRX0, kvm_vcpu, arch.dawrx0);
+	OFFSET(VCPU_DAWR1, kvm_vcpu, arch.dawr1);
+	OFFSET(VCPU_DAWRX1, kvm_vcpu, arch.dawrx1);
 	OFFSET(VCPU_CIABR, kvm_vcpu, arch.ciabr);
 	OFFSET(VCPU_HFLAGS, kvm_vcpu, arch.hflags);
 	OFFSET(VCPU_DEC, kvm_vcpu, arch.dec);

arch/powerpc/kvm/book3s_hv.c

@@ -785,6 +785,22 @@ static int kvmppc_h_set_mode(struct kvm_vcpu *vcpu, unsigned long mflags,
 		vcpu->arch.dawr0  = value1;
 		vcpu->arch.dawrx0 = value2;
 		return H_SUCCESS;
+	case H_SET_MODE_RESOURCE_SET_DAWR1:
+		if (!kvmppc_power8_compatible(vcpu))
+			return H_P2;
+		if (!ppc_breakpoint_available())
+			return H_P2;
+		if (!cpu_has_feature(CPU_FTR_DAWR1))
+			return H_P2;
+		if (!vcpu->kvm->arch.dawr1_enabled)
+			return H_FUNCTION;
+		if (mflags)
+			return H_UNSUPPORTED_FLAG_START;
+		if (value2 & DABRX_HYP)
+			return H_P4;
+		vcpu->arch.dawr1  = value1;
+		vcpu->arch.dawrx1 = value2;
+		return H_SUCCESS;
 	case H_SET_MODE_RESOURCE_ADDR_TRANS_MODE:
 		/* KVM does not support mflags=2 (AIL=2) */
 		if (mflags != 0 && mflags != 3)
@@ -1764,6 +1780,12 @@ static int kvmppc_get_one_reg_hv(struct kvm_vcpu *vcpu, u64 id,
 	case KVM_REG_PPC_DAWRX:
 		*val = get_reg_val(id, vcpu->arch.dawrx0);
 		break;
+	case KVM_REG_PPC_DAWR1:
+		*val = get_reg_val(id, vcpu->arch.dawr1);
+		break;
+	case KVM_REG_PPC_DAWRX1:
+		*val = get_reg_val(id, vcpu->arch.dawrx1);
+		break;
 	case KVM_REG_PPC_CIABR:
 		*val = get_reg_val(id, vcpu->arch.ciabr);
 		break;
@@ -1996,6 +2018,12 @@ static int kvmppc_set_one_reg_hv(struct kvm_vcpu *vcpu, u64 id,
 	case KVM_REG_PPC_DAWRX:
 		vcpu->arch.dawrx0 = set_reg_val(id, *val) & ~DAWRX_HYP;
 		break;
+	case KVM_REG_PPC_DAWR1:
+		vcpu->arch.dawr1 = set_reg_val(id, *val);
+		break;
+	case KVM_REG_PPC_DAWRX1:
+		vcpu->arch.dawrx1 = set_reg_val(id, *val) & ~DAWRX_HYP;
+		break;
 	case KVM_REG_PPC_CIABR:
 		vcpu->arch.ciabr = set_reg_val(id, *val);
 		/* Don't allow setting breakpoints in hypervisor code */
@@ -3453,6 +3481,13 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 	unsigned long host_dawrx0 = mfspr(SPRN_DAWRX0);
 	unsigned long host_psscr = mfspr(SPRN_PSSCR);
 	unsigned long host_pidr = mfspr(SPRN_PID);
+	unsigned long host_dawr1 = 0;
+	unsigned long host_dawrx1 = 0;
+
+	if (cpu_has_feature(CPU_FTR_DAWR1)) {
+		host_dawr1 = mfspr(SPRN_DAWR1);
+		host_dawrx1 = mfspr(SPRN_DAWRX1);
+	}
 
 	/*
 	 * P8 and P9 suppress the HDEC exception when LPCR[HDICE] = 0,
@@ -3491,6 +3526,10 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 	if (dawr_enabled()) {
 		mtspr(SPRN_DAWR0, vcpu->arch.dawr0);
 		mtspr(SPRN_DAWRX0, vcpu->arch.dawrx0);
+		if (cpu_has_feature(CPU_FTR_DAWR1)) {
+			mtspr(SPRN_DAWR1, vcpu->arch.dawr1);
+			mtspr(SPRN_DAWRX1, vcpu->arch.dawrx1);
+		}
 	}
 	mtspr(SPRN_CIABR, vcpu->arch.ciabr);
 	mtspr(SPRN_IC, vcpu->arch.ic);
@@ -3544,6 +3583,10 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
 	mtspr(SPRN_CIABR, host_ciabr);
 	mtspr(SPRN_DAWR0, host_dawr0);
 	mtspr(SPRN_DAWRX0, host_dawrx0);
+	if (cpu_has_feature(CPU_FTR_DAWR1)) {
+		mtspr(SPRN_DAWR1, host_dawr1);
+		mtspr(SPRN_DAWRX1, host_dawrx1);
+	}
 	mtspr(SPRN_PID, host_pidr);
 
 	/*

arch/powerpc/kvm/book3s_hv_nested.c

@@ -49,6 +49,8 @@ void kvmhv_save_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr)
 	hr->pidr = vcpu->arch.pid;
 	hr->cfar = vcpu->arch.cfar;
 	hr->ppr = vcpu->arch.ppr;
+	hr->dawr1 = vcpu->arch.dawr1;
+	hr->dawrx1 = vcpu->arch.dawrx1;
 }
 
 static void byteswap_pt_regs(struct pt_regs *regs)
@@ -91,6 +93,8 @@ static void byteswap_hv_regs(struct hv_guest_state *hr)
 	hr->pidr = swab64(hr->pidr);
 	hr->cfar = swab64(hr->cfar);
 	hr->ppr = swab64(hr->ppr);
+	hr->dawr1 = swab64(hr->dawr1);
+	hr->dawrx1 = swab64(hr->dawrx1);
 }
 
 static void save_hv_return_state(struct kvm_vcpu *vcpu, int trap,
@@ -138,6 +142,7 @@ static void sanitise_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr)
 
 	/* Don't let data address watchpoint match in hypervisor state */
 	hr->dawrx0 &= ~DAWRX_HYP;
+	hr->dawrx1 &= ~DAWRX_HYP;
 
 	/* Don't let completed instruction address breakpt match in HV state */
 	if ((hr->ciabr & CIABR_PRIV) == CIABR_PRIV_HYPER)
@@ -167,6 +172,8 @@ static void restore_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr)
 	vcpu->arch.pid = hr->pidr;
 	vcpu->arch.cfar = hr->cfar;
 	vcpu->arch.ppr = hr->ppr;
+	vcpu->arch.dawr1 = hr->dawr1;
+	vcpu->arch.dawrx1 = hr->dawrx1;
 }
 
 void kvmhv_restore_hv_return_state(struct kvm_vcpu *vcpu,

arch/powerpc/kvm/book3s_hv_rmhandlers.S

@@ -57,6 +57,8 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
 #define STACK_SLOT_HFSCR	(SFS-72)
 #define STACK_SLOT_AMR		(SFS-80)
 #define STACK_SLOT_UAMOR	(SFS-88)
+#define STACK_SLOT_DAWR1	(SFS-96)
+#define STACK_SLOT_DAWRX1	(SFS-104)
 /* the following is used by the P9 short path */
 #define STACK_SLOT_NVGPRS	(SFS-152)	/* 18 gprs */
 
@@ -715,6 +717,12 @@ BEGIN_FTR_SECTION
 	std	r7, STACK_SLOT_DAWRX0(r1)
 	std	r8, STACK_SLOT_IAMR(r1)
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
+BEGIN_FTR_SECTION
+	mfspr	r6, SPRN_DAWR1
+	mfspr	r7, SPRN_DAWRX1
+	std	r6, STACK_SLOT_DAWR1(r1)
+	std	r7, STACK_SLOT_DAWRX1(r1)
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S | CPU_FTR_DAWR1)
 
 	mfspr	r5, SPRN_AMR
 	std	r5, STACK_SLOT_AMR(r1)
@@ -805,6 +813,12 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 	ld	r6, VCPU_DAWRX0(r4)
 	mtspr	SPRN_DAWR0, r5
 	mtspr	SPRN_DAWRX0, r6
+BEGIN_FTR_SECTION
+	ld	r5, VCPU_DAWR1(r4)
+	ld	r6, VCPU_DAWRX1(r4)
+	mtspr	SPRN_DAWR1, r5
+	mtspr	SPRN_DAWRX1, r6
+END_FTR_SECTION_IFSET(CPU_FTR_DAWR1)
 1:
 	ld	r7, VCPU_CIABR(r4)
 	ld	r8, VCPU_TAR(r4)
@@ -1769,6 +1783,12 @@ BEGIN_FTR_SECTION
 	mtspr	SPRN_DAWR0, r6
 	mtspr	SPRN_DAWRX0, r7
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
+BEGIN_FTR_SECTION
+	ld	r6, STACK_SLOT_DAWR1(r1)
+	ld	r7, STACK_SLOT_DAWRX1(r1)
+	mtspr	SPRN_DAWR1, r6
+	mtspr	SPRN_DAWRX1, r7
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S | CPU_FTR_DAWR1)
 BEGIN_FTR_SECTION
 	ld	r5, STACK_SLOT_TID(r1)
 	ld	r6, STACK_SLOT_PSSCR(r1)
@@ -3343,6 +3363,9 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
 	mtspr	SPRN_IAMR, r0
 	mtspr	SPRN_CIABR, r0
 	mtspr	SPRN_DAWRX0, r0
+BEGIN_FTR_SECTION
+	mtspr	SPRN_DAWRX1, r0
+END_FTR_SECTION_IFSET(CPU_FTR_DAWR1)
 
 BEGIN_MMU_FTR_SECTION
 	b	4f

tools/arch/powerpc/include/uapi/asm/kvm.h

@@ -644,6 +644,8 @@ struct kvm_ppc_cpu_char {
 #define KVM_REG_PPC_MMCR3	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xc1)
 #define KVM_REG_PPC_SIER2	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xc2)
 #define KVM_REG_PPC_SIER3	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xc3)
+#define KVM_REG_PPC_DAWR1	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xc4)
+#define KVM_REG_PPC_DAWRX1	(KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xc5)
 
 /* Transactional Memory checkpointed state:
  * This is all GPRs, all VSX regs and a subset of SPRs