1 files changed, 102 insertions, 84 deletions

diff --git a/arch/arm64/kvm/at.c b/arch/arm64/kvm/at.c
index f74a66ce3064..a25be111cd8f 100644
--- a/arch/arm64/kvm/at.c
+++ b/arch/arm64/kvm/at.c
@@ -10,61 +10,11 @@
 #include <asm/kvm_hyp.h>
 #include <asm/kvm_mmu.h>
 
-enum trans_regime {
-	TR_EL10,
-	TR_EL20,
-	TR_EL2,
-};
-
-struct s1_walk_info {
-	u64	     		baddr;
-	enum trans_regime	regime;
-	unsigned int		max_oa_bits;
-	unsigned int		pgshift;
-	unsigned int		txsz;
-	int 	     		sl;
-	bool	     		hpd;
-	bool			e0poe;
-	bool			poe;
-	bool			pan;
-	bool	     		be;
-	bool	     		s2;
-};
-
-struct s1_walk_result {
-	union {
-		struct {
-			u64	desc;
-			u64	pa;
-			s8	level;
-			u8	APTable;
-			bool	UXNTable;
-			bool	PXNTable;
-			bool	uwxn;
-			bool	uov;
-			bool	ur;
-			bool	uw;
-			bool	ux;
-			bool	pwxn;
-			bool	pov;
-			bool	pr;
-			bool	pw;
-			bool	px;
-		};
-		struct {
-			u8	fst;
-			bool	ptw;
-			bool	s2;
-		};
-	};
-	bool	failed;
-};
-
-static void fail_s1_walk(struct s1_walk_result *wr, u8 fst, bool ptw, bool s2)
+static void fail_s1_walk(struct s1_walk_result *wr, u8 fst, bool s1ptw)
 {
 	wr->fst		= fst;
-	wr->ptw		= ptw;
-	wr->s2		= s2;
+	wr->ptw		= s1ptw;
+	wr->s2		= s1ptw;
 	wr->failed	= true;
 }
 
@@ -145,20 +95,15 @@ static void compute_s1poe(struct kvm_vcpu *vcpu, struct s1_walk_info *wi)
 	}
 }
 
-static int setup_s1_walk(struct kvm_vcpu *vcpu, u32 op, struct s1_walk_info *wi,
+static int setup_s1_walk(struct kvm_vcpu *vcpu, struct s1_walk_info *wi,
 			 struct s1_walk_result *wr, u64 va)
 {
 	u64 hcr, sctlr, tcr, tg, ps, ia_bits, ttbr;
 	unsigned int stride, x;
-	bool va55, tbi, lva, as_el0;
+	bool va55, tbi, lva;
 
 	hcr = __vcpu_sys_reg(vcpu, HCR_EL2);
 
-	wi->regime = compute_translation_regime(vcpu, op);
-	as_el0 = (op == OP_AT_S1E0R || op == OP_AT_S1E0W);
-	wi->pan = (op == OP_AT_S1E1RP || op == OP_AT_S1E1WP) &&
-		  (*vcpu_cpsr(vcpu) & PSR_PAN_BIT);
-
 	va55 = va & BIT(55);
 
 	if (wi->regime == TR_EL2 && va55)
@@ -319,7 +264,7 @@ static int setup_s1_walk(struct kvm_vcpu *vcpu, u32 op, struct s1_walk_info *wi,
 
 	/* R_BNDVG and following statements */
 	if (kvm_has_feat(vcpu->kvm, ID_AA64MMFR2_EL1, E0PD, IMP) &&
-	    as_el0 && (tcr & (va55 ? TCR_E0PD1 : TCR_E0PD0)))
+	    wi->as_el0 && (tcr & (va55 ? TCR_E0PD1 : TCR_E0PD0)))
 		goto transfault_l0;
 
 	/* AArch64.S1StartLevel() */
@@ -345,11 +290,11 @@ static int setup_s1_walk(struct kvm_vcpu *vcpu, u32 op, struct s1_walk_info *wi,
 	return 0;
 
 addrsz:				/* Address Size Fault level 0 */
-	fail_s1_walk(wr, ESR_ELx_FSC_ADDRSZ_L(0), false, false);
+	fail_s1_walk(wr, ESR_ELx_FSC_ADDRSZ_L(0), false);
 	return -EFAULT;
 
 transfault_l0:			/* Translation Fault level 0 */
-	fail_s1_walk(wr, ESR_ELx_FSC_FAULT_L(0), false, false);
+	fail_s1_walk(wr, ESR_ELx_FSC_FAULT_L(0), false);
 	return -EFAULT;
 }
 
@@ -380,13 +325,13 @@ static int walk_s1(struct kvm_vcpu *vcpu, struct s1_walk_info *wi,
 			if (ret) {
 				fail_s1_walk(wr,
 					     (s2_trans.esr & ~ESR_ELx_FSC_LEVEL) | level,
-					     true, true);
+					     true);
 				return ret;
 			}
 
 			if (!kvm_s2_trans_readable(&s2_trans)) {
 				fail_s1_walk(wr, ESR_ELx_FSC_PERM_L(level),
-					     true, true);
+					     true);
 
 				return -EPERM;
 			}
@@ -396,8 +341,7 @@ static int walk_s1(struct kvm_vcpu *vcpu, struct s1_walk_info *wi,
 
 		ret = kvm_read_guest(vcpu->kvm, ipa, &desc, sizeof(desc));
 		if (ret) {
-			fail_s1_walk(wr, ESR_ELx_FSC_SEA_TTW(level),
-				     true, false);
+			fail_s1_walk(wr, ESR_ELx_FSC_SEA_TTW(level), false);
 			return ret;
 		}
 
@@ -457,6 +401,11 @@ static int walk_s1(struct kvm_vcpu *vcpu, struct s1_walk_info *wi,
 	if (check_output_size(desc & GENMASK(47, va_bottom), wi))
 		goto addrsz;
 
+	if (!(desc & PTE_AF)) {
+		fail_s1_walk(wr, ESR_ELx_FSC_ACCESS_L(level), false);
+		return -EACCES;
+	}
+
 	va_bottom += contiguous_bit_shift(desc, wi, level);
 
 	wr->failed = false;
@@ -465,13 +414,40 @@ static int walk_s1(struct kvm_vcpu *vcpu, struct s1_walk_info *wi,
 	wr->pa = desc & GENMASK(47, va_bottom);
 	wr->pa |= va & GENMASK_ULL(va_bottom - 1, 0);
 
+	wr->nG = (wi->regime != TR_EL2) && (desc & PTE_NG);
+	if (wr->nG) {
+		u64 asid_ttbr, tcr;
+
+		switch (wi->regime) {
+		case TR_EL10:
+			tcr = vcpu_read_sys_reg(vcpu, TCR_EL1);
+			asid_ttbr = ((tcr & TCR_A1) ?
+				     vcpu_read_sys_reg(vcpu, TTBR1_EL1) :
+				     vcpu_read_sys_reg(vcpu, TTBR0_EL1));
+			break;
+		case TR_EL20:
+			tcr = vcpu_read_sys_reg(vcpu, TCR_EL2);
+			asid_ttbr = ((tcr & TCR_A1) ?
+				     vcpu_read_sys_reg(vcpu, TTBR1_EL2) :
+				     vcpu_read_sys_reg(vcpu, TTBR0_EL2));
+			break;
+		default:
+			BUG();
+		}
+
+		wr->asid = FIELD_GET(TTBR_ASID_MASK, asid_ttbr);
+		if (!kvm_has_feat_enum(vcpu->kvm, ID_AA64MMFR0_EL1, ASIDBITS, 16) ||
+		    !(tcr & TCR_ASID16))
+			wr->asid &= GENMASK(7, 0);
+	}
+
 	return 0;
 
 addrsz:
-	fail_s1_walk(wr, ESR_ELx_FSC_ADDRSZ_L(level), true, false);
+	fail_s1_walk(wr, ESR_ELx_FSC_ADDRSZ_L(level), false);
 	return -EINVAL;
 transfault:
-	fail_s1_walk(wr, ESR_ELx_FSC_FAULT_L(level), true, false);
+	fail_s1_walk(wr, ESR_ELx_FSC_FAULT_L(level), false);
 	return -ENOENT;
 }
 
@@ -488,7 +464,6 @@ struct mmu_config {
 	u64	sctlr;
 	u64	vttbr;
 	u64	vtcr;
-	u64	hcr;
 };
 
 static void __mmu_config_save(struct mmu_config *config)
@@ -511,13 +486,10 @@ static void __mmu_config_save(struct mmu_config *config)
 	config->sctlr	= read_sysreg_el1(SYS_SCTLR);
 	config->vttbr	= read_sysreg(vttbr_el2);
 	config->vtcr	= read_sysreg(vtcr_el2);
-	config->hcr	= read_sysreg(hcr_el2);
 }
 
 static void __mmu_config_restore(struct mmu_config *config)
 {
-	write_sysreg(config->hcr,	hcr_el2);
-
 	/*
 	 * ARM errata 1165522 and 1530923 require TGE to be 1 before
 	 * we update the guest state.
@@ -1155,7 +1127,12 @@ static u64 handle_at_slow(struct kvm_vcpu *vcpu, u32 op, u64 vaddr)
 	bool perm_fail = false;
 	int ret, idx;
 
-	ret = setup_s1_walk(vcpu, op, &wi, &wr, vaddr);
+	wi.regime = compute_translation_regime(vcpu, op);
+	wi.as_el0 = (op == OP_AT_S1E0R || op == OP_AT_S1E0W);
+	wi.pan = (op == OP_AT_S1E1RP || op == OP_AT_S1E1WP) &&
+		 (*vcpu_cpsr(vcpu) & PSR_PAN_BIT);
+
+	ret = setup_s1_walk(vcpu, &wi, &wr, vaddr);
 	if (ret)
 		goto compute_par;
 
@@ -1198,7 +1175,7 @@ static u64 handle_at_slow(struct kvm_vcpu *vcpu, u32 op, u64 vaddr)
 	}
 
 	if (perm_fail)
-		fail_s1_walk(&wr, ESR_ELx_FSC_PERM_L(wr.level), false, false);
+		fail_s1_walk(&wr, ESR_ELx_FSC_PERM_L(wr.level), false);
 
 compute_par:
 	return compute_par_s1(vcpu, &wr, wi.regime);
@@ -1210,7 +1187,8 @@ compute_par:
  * If the translation is unsuccessful, the value may only contain
  * PAR_EL1.F, and cannot be taken at face value. It isn't an
  * indication of the translation having failed, only that the fast
- * path did not succeed, *unless* it indicates a S1 permission fault.
+ * path did not succeed, *unless* it indicates a S1 permission or
+ * access fault.
  */
 static u64 __kvm_at_s1e01_fast(struct kvm_vcpu *vcpu, u32 op, u64 vaddr)
 {
@@ -1266,8 +1244,8 @@ static u64 __kvm_at_s1e01_fast(struct kvm_vcpu *vcpu, u32 op, u64 vaddr)
 	__load_stage2(mmu, mmu->arch);
 
 skip_mmu_switch:
-	/* Clear TGE, enable S2 translation, we're rolling */
-	write_sysreg((config.hcr & ~HCR_TGE) | HCR_VM,	hcr_el2);
+	/* Temporarily switch back to guest context */
+	write_sysreg_hcr(vcpu->arch.hcr_el2);
 	isb();
 
 	switch (op) {
@@ -1299,6 +1277,8 @@ skip_mmu_switch:
 	if (!fail)
 		par = read_sysreg_par();
 
+	write_sysreg_hcr(HCR_HOST_VHE_FLAGS);
+
 	if (!(vcpu_el2_e2h_is_set(vcpu) && vcpu_el2_tge_is_set(vcpu)))
 		__mmu_config_restore(&config);
 
@@ -1313,19 +1293,29 @@ static bool par_check_s1_perm_fault(u64 par)
 		 !(par & SYS_PAR_EL1_S));
 }
 
+static bool par_check_s1_access_fault(u64 par)
+{
+	u8 fst = FIELD_GET(SYS_PAR_EL1_FST, par);
+
+	return  ((fst & ESR_ELx_FSC_TYPE) == ESR_ELx_FSC_ACCESS &&
+		 !(par & SYS_PAR_EL1_S));
+}
+
 void __kvm_at_s1e01(struct kvm_vcpu *vcpu, u32 op, u64 vaddr)
 {
 	u64 par = __kvm_at_s1e01_fast(vcpu, op, vaddr);
 
 	/*
-	 * If PAR_EL1 reports that AT failed on a S1 permission fault, we
-	 * know for sure that the PTW was able to walk the S1 tables and
-	 * there's nothing else to do.
+	 * If PAR_EL1 reports that AT failed on a S1 permission or access
+	 * fault, we know for sure that the PTW was able to walk the S1
+	 * tables and there's nothing else to do.
 	 *
 	 * If AT failed for any other reason, then we must walk the guest S1
 	 * to emulate the instruction.
 	 */
-	if ((par & SYS_PAR_EL1_F) && !par_check_s1_perm_fault(par))
+	if ((par & SYS_PAR_EL1_F) &&
+	    !par_check_s1_perm_fault(par) &&
+	    !par_check_s1_access_fault(par))
 		par = handle_at_slow(vcpu, op, vaddr);
 
 	vcpu_write_sys_reg(vcpu, par, PAR_EL1);
@@ -1350,7 +1340,7 @@ void __kvm_at_s1e2(struct kvm_vcpu *vcpu, u32 op, u64 vaddr)
 		if (!vcpu_el2_e2h_is_set(vcpu))
 			val |= HCR_NV | HCR_NV1;
 
-		write_sysreg(val, hcr_el2);
+		write_sysreg_hcr(val);
 		isb();
 
 		par = SYS_PAR_EL1_F;
@@ -1375,7 +1365,7 @@ void __kvm_at_s1e2(struct kvm_vcpu *vcpu, u32 op, u64 vaddr)
 		if (!fail)
 			par = read_sysreg_par();
 
-		write_sysreg(hcr, hcr_el2);
+		write_sysreg_hcr(hcr);
 		isb();
 	}
 
@@ -1444,3 +1434,31 @@ void __kvm_at_s12(struct kvm_vcpu *vcpu, u32 op, u64 vaddr)
 	par = compute_par_s12(vcpu, par, &out);
 	vcpu_write_sys_reg(vcpu, par, PAR_EL1);
 }
+
+/*
+ * Translate a VA for a given EL in a given translation regime, with
+ * or without PAN. This requires wi->{regime, as_el0, pan} to be
+ * set. The rest of the wi and wr should be 0-initialised.
+ */
+int __kvm_translate_va(struct kvm_vcpu *vcpu, struct s1_walk_info *wi,
+		       struct s1_walk_result *wr, u64 va)
+{
+	int ret;
+
+	ret = setup_s1_walk(vcpu, wi, wr, va);
+	if (ret)
+		return ret;
+
+	if (wr->level == S1_MMU_DISABLED) {
+		wr->ur = wr->uw = wr->ux = true;
+		wr->pr = wr->pw = wr->px = true;
+	} else {
+		ret = walk_s1(vcpu, wi, wr, va);
+		if (ret)
+			return ret;
+
+		compute_s1_permissions(vcpu, wi, wr);
+	}
+
+	return 0;
+}