1 files changed, 212 insertions, 55 deletions

diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c
index f32f4a2a347f..dfcd66c65517 100644
--- a/arch/arm64/kvm/inject_fault.c
+++ b/arch/arm64/kvm/inject_fault.c
@@ -12,17 +12,130 @@
 
 #include <linux/kvm_host.h>
 #include <asm/kvm_emulate.h>
+#include <asm/kvm_nested.h>
 #include <asm/esr.h>
 
+static unsigned int exception_target_el(struct kvm_vcpu *vcpu)
+{
+	/* If not nesting, EL1 is the only possible exception target */
+	if (likely(!vcpu_has_nv(vcpu)))
+		return PSR_MODE_EL1h;
+
+	/*
+	 * With NV, we need to pick between EL1 and EL2. Note that we
+	 * never deal with a nesting exception here, hence never
+	 * changing context, and the exception itself can be delayed
+	 * until the next entry.
+	 */
+	switch(*vcpu_cpsr(vcpu) & PSR_MODE_MASK) {
+	case PSR_MODE_EL2h:
+	case PSR_MODE_EL2t:
+		return PSR_MODE_EL2h;
+	case PSR_MODE_EL1h:
+	case PSR_MODE_EL1t:
+		return PSR_MODE_EL1h;
+	case PSR_MODE_EL0t:
+		return vcpu_el2_tge_is_set(vcpu) ? PSR_MODE_EL2h : PSR_MODE_EL1h;
+	default:
+		BUG();
+	}
+}
+
+static enum vcpu_sysreg exception_esr_elx(struct kvm_vcpu *vcpu)
+{
+	if (exception_target_el(vcpu) == PSR_MODE_EL2h)
+		return ESR_EL2;
+
+	return ESR_EL1;
+}
+
+static enum vcpu_sysreg exception_far_elx(struct kvm_vcpu *vcpu)
+{
+	if (exception_target_el(vcpu) == PSR_MODE_EL2h)
+		return FAR_EL2;
+
+	return FAR_EL1;
+}
+
+static void pend_sync_exception(struct kvm_vcpu *vcpu)
+{
+	if (exception_target_el(vcpu) == PSR_MODE_EL1h)
+		kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC);
+	else
+		kvm_pend_exception(vcpu, EXCEPT_AA64_EL2_SYNC);
+}
+
+static void pend_serror_exception(struct kvm_vcpu *vcpu)
+{
+	if (exception_target_el(vcpu) == PSR_MODE_EL1h)
+		kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SERR);
+	else
+		kvm_pend_exception(vcpu, EXCEPT_AA64_EL2_SERR);
+}
+
+static bool __effective_sctlr2_bit(struct kvm_vcpu *vcpu, unsigned int idx)
+{
+	u64 sctlr2;
+
+	if (!kvm_has_sctlr2(vcpu->kvm))
+		return false;
+
+	if (is_nested_ctxt(vcpu) &&
+	    !(__vcpu_sys_reg(vcpu, HCRX_EL2) & HCRX_EL2_SCTLR2En))
+		return false;
+
+	if (exception_target_el(vcpu) == PSR_MODE_EL1h)
+		sctlr2 = vcpu_read_sys_reg(vcpu, SCTLR2_EL1);
+	else
+		sctlr2 = vcpu_read_sys_reg(vcpu, SCTLR2_EL2);
+
+	return sctlr2 & BIT(idx);
+}
+
+static bool effective_sctlr2_ease(struct kvm_vcpu *vcpu)
+{
+	return __effective_sctlr2_bit(vcpu, SCTLR2_EL1_EASE_SHIFT);
+}
+
+static bool effective_sctlr2_nmea(struct kvm_vcpu *vcpu)
+{
+	return __effective_sctlr2_bit(vcpu, SCTLR2_EL1_NMEA_SHIFT);
+}
+
 static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr)
 {
 	unsigned long cpsr = *vcpu_cpsr(vcpu);
 	bool is_aarch32 = vcpu_mode_is_32bit(vcpu);
-	u64 esr = 0;
+	u64 esr = 0, fsc;
+	int level;
 
-	kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC);
+	/*
+	 * If injecting an abort from a failed S1PTW, rewalk the S1 PTs to
+	 * find the failing level. If we can't find it, assume the error was
+	 * transient and restart without changing the state.
+	 */
+	if (kvm_vcpu_abt_iss1tw(vcpu)) {
+		u64 hpfar = kvm_vcpu_get_fault_ipa(vcpu);
+		int ret;
+
+		if (hpfar == INVALID_GPA)
+			return;
+
+		ret = __kvm_find_s1_desc_level(vcpu, addr, hpfar, &level);
+		if (ret)
+			return;
+
+		WARN_ON_ONCE(level < -1 || level > 3);
+		fsc = ESR_ELx_FSC_SEA_TTW(level);
+	} else {
+		fsc = ESR_ELx_FSC_EXTABT;
+	}
 
-	vcpu_write_sys_reg(vcpu, addr, FAR_EL1);
+	/* This delight is brought to you by FEAT_DoubleFault2. */
+	if (effective_sctlr2_ease(vcpu))
+		pend_serror_exception(vcpu);
+	else
+		pend_sync_exception(vcpu);
 
 	/*
 	 * Build an {i,d}abort, depending on the level and the
@@ -43,14 +156,17 @@ static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr
 	if (!is_iabt)
 		esr |= ESR_ELx_EC_DABT_LOW << ESR_ELx_EC_SHIFT;
 
-	vcpu_write_sys_reg(vcpu, esr | ESR_ELx_FSC_EXTABT, ESR_EL1);
+	esr |= fsc;
+
+	vcpu_write_sys_reg(vcpu, addr, exception_far_elx(vcpu));
+	vcpu_write_sys_reg(vcpu, esr, exception_esr_elx(vcpu));
 }
 
 static void inject_undef64(struct kvm_vcpu *vcpu)
 {
 	u64 esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT);
 
-	kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC);
+	pend_sync_exception(vcpu);
 
 	/*
 	 * Build an unknown exception, depending on the instruction
@@ -59,7 +175,7 @@ static void inject_undef64(struct kvm_vcpu *vcpu)
 	if (kvm_vcpu_trap_il_is32bit(vcpu))
 		esr |= ESR_ELx_IL;
 
-	vcpu_write_sys_reg(vcpu, esr, ESR_EL1);
+	vcpu_write_sys_reg(vcpu, esr, exception_esr_elx(vcpu));
 }
 
 #define DFSR_FSC_EXTABT_LPAE	0x10
@@ -85,7 +201,7 @@ static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt, u32 addr)
 	if (vcpu_read_sys_reg(vcpu, TCR_EL1) & TTBCR_EAE) {
 		fsr = DFSR_LPAE | DFSR_FSC_EXTABT_LPAE;
 	} else {
-		/* no need to shuffle FS[4] into DFSR[10] as its 0 */
+		/* no need to shuffle FS[4] into DFSR[10] as it's 0 */
 		fsr = DFSR_FSC_EXTABT_nLPAE;
 	}
 
@@ -106,36 +222,35 @@ static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt, u32 addr)
 	vcpu_write_sys_reg(vcpu, far, FAR_EL1);
 }
 
-/**
- * kvm_inject_dabt - inject a data abort into the guest
- * @vcpu: The VCPU to receive the data abort
- * @addr: The address to report in the DFAR
- *
- * It is assumed that this code is called from the VCPU thread and that the
- * VCPU therefore is not currently executing guest code.
- */
-void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr)
+static void __kvm_inject_sea(struct kvm_vcpu *vcpu, bool iabt, u64 addr)
 {
 	if (vcpu_el1_is_32bit(vcpu))
-		inject_abt32(vcpu, false, addr);
+		inject_abt32(vcpu, iabt, addr);
 	else
-		inject_abt64(vcpu, false, addr);
+		inject_abt64(vcpu, iabt, addr);
 }
 
-/**
- * kvm_inject_pabt - inject a prefetch abort into the guest
- * @vcpu: The VCPU to receive the prefetch abort
- * @addr: The address to report in the DFAR
- *
- * It is assumed that this code is called from the VCPU thread and that the
- * VCPU therefore is not currently executing guest code.
- */
-void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr)
+static bool kvm_sea_target_is_el2(struct kvm_vcpu *vcpu)
 {
-	if (vcpu_el1_is_32bit(vcpu))
-		inject_abt32(vcpu, true, addr);
-	else
-		inject_abt64(vcpu, true, addr);
+	if (__vcpu_sys_reg(vcpu, HCR_EL2) & (HCR_TGE | HCR_TEA))
+		return true;
+
+	if (!vcpu_mode_priv(vcpu))
+		return false;
+
+	return (*vcpu_cpsr(vcpu) & PSR_A_BIT) &&
+	       (__vcpu_sys_reg(vcpu, HCRX_EL2) & HCRX_EL2_TMEA);
+}
+
+int kvm_inject_sea(struct kvm_vcpu *vcpu, bool iabt, u64 addr)
+{
+	lockdep_assert_held(&vcpu->mutex);
+
+	if (is_nested_ctxt(vcpu) && kvm_sea_target_is_el2(vcpu))
+		return kvm_inject_nested_sea(vcpu, iabt, addr);
+
+	__kvm_inject_sea(vcpu, iabt, addr);
+	return 1;
 }
 
 void kvm_inject_size_fault(struct kvm_vcpu *vcpu)
@@ -145,25 +260,22 @@ void kvm_inject_size_fault(struct kvm_vcpu *vcpu)
 	addr  = kvm_vcpu_get_fault_ipa(vcpu);
 	addr |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0);
 
-	if (kvm_vcpu_trap_is_iabt(vcpu))
-		kvm_inject_pabt(vcpu, addr);
-	else
-		kvm_inject_dabt(vcpu, addr);
+	__kvm_inject_sea(vcpu, kvm_vcpu_trap_is_iabt(vcpu), addr);
 
 	/*
 	 * If AArch64 or LPAE, set FSC to 0 to indicate an Address
 	 * Size Fault at level 0, as if exceeding PARange.
 	 *
 	 * Non-LPAE guests will only get the external abort, as there
-	 * is no way to to describe the ASF.
+	 * is no way to describe the ASF.
 	 */
 	if (vcpu_el1_is_32bit(vcpu) &&
 	    !(vcpu_read_sys_reg(vcpu, TCR_EL1) & TTBCR_EAE))
 		return;
 
-	esr = vcpu_read_sys_reg(vcpu, ESR_EL1);
+	esr = vcpu_read_sys_reg(vcpu, exception_esr_elx(vcpu));
 	esr &= ~GENMASK_ULL(5, 0);
-	vcpu_write_sys_reg(vcpu, esr, ESR_EL1);
+	vcpu_write_sys_reg(vcpu, esr, exception_esr_elx(vcpu));
 }
 
 /**
@@ -181,25 +293,70 @@ void kvm_inject_undefined(struct kvm_vcpu *vcpu)
 		inject_undef64(vcpu);
 }
 
-void kvm_set_sei_esr(struct kvm_vcpu *vcpu, u64 esr)
+static bool serror_is_masked(struct kvm_vcpu *vcpu)
 {
-	vcpu_set_vsesr(vcpu, esr & ESR_ELx_ISS_MASK);
-	*vcpu_hcr(vcpu) |= HCR_VSE;
+	return (*vcpu_cpsr(vcpu) & PSR_A_BIT) && !effective_sctlr2_nmea(vcpu);
 }
 
-/**
- * kvm_inject_vabt - inject an async abort / SError into the guest
- * @vcpu: The VCPU to receive the exception
- *
- * It is assumed that this code is called from the VCPU thread and that the
- * VCPU therefore is not currently executing guest code.
- *
- * Systems with the RAS Extensions specify an imp-def ESR (ISV/IDS = 1) with
- * the remaining ISS all-zeros so that this error is not interpreted as an
- * uncategorized RAS error. Without the RAS Extensions we can't specify an ESR
- * value, so the CPU generates an imp-def value.
- */
-void kvm_inject_vabt(struct kvm_vcpu *vcpu)
+static bool kvm_serror_target_is_el2(struct kvm_vcpu *vcpu)
 {
-	kvm_set_sei_esr(vcpu, ESR_ELx_ISV);
+	if (is_hyp_ctxt(vcpu) || vcpu_el2_amo_is_set(vcpu))
+		return true;
+
+	if (!(__vcpu_sys_reg(vcpu, HCRX_EL2) & HCRX_EL2_TMEA))
+		return false;
+
+	/*
+	 * In another example where FEAT_DoubleFault2 is entirely backwards,
+	 * "masked" as it relates to the routing effects of HCRX_EL2.TMEA
+	 * doesn't consider SCTLR2_EL1.NMEA. That is to say, even if EL1 asked
+	 * for non-maskable SErrors, the EL2 bit takes priority if A is set.
+	 */
+	if (vcpu_mode_priv(vcpu))
+		return *vcpu_cpsr(vcpu) & PSR_A_BIT;
+
+	/*
+	 * Otherwise SErrors are considered unmasked when taken from EL0 and
+	 * NMEA is set.
+	 */
+	return serror_is_masked(vcpu);
+}
+
+static bool kvm_serror_undeliverable_at_el2(struct kvm_vcpu *vcpu)
+{
+	return !(vcpu_el2_tge_is_set(vcpu) || vcpu_el2_amo_is_set(vcpu));
+}
+
+int kvm_inject_serror_esr(struct kvm_vcpu *vcpu, u64 esr)
+{
+	lockdep_assert_held(&vcpu->mutex);
+
+	if (is_nested_ctxt(vcpu) && kvm_serror_target_is_el2(vcpu))
+		return kvm_inject_nested_serror(vcpu, esr);
+
+	if (vcpu_is_el2(vcpu) && kvm_serror_undeliverable_at_el2(vcpu)) {
+		vcpu_set_vsesr(vcpu, esr);
+		vcpu_set_flag(vcpu, NESTED_SERROR_PENDING);
+		return 1;
+	}
+
+	/*
+	 * Emulate the exception entry if SErrors are unmasked. This is useful if
+	 * the vCPU is in a nested context w/ vSErrors enabled then we've already
+	 * delegated he hardware vSError context (i.e. HCR_EL2.VSE, VSESR_EL2,
+	 * VDISR_EL2) to the guest hypervisor.
+	 *
+	 * As we're emulating the SError injection we need to explicitly populate
+	 * ESR_ELx.EC because hardware will not do it on our behalf.
+	 */
+	if (!serror_is_masked(vcpu)) {
+		pend_serror_exception(vcpu);
+		esr |= FIELD_PREP(ESR_ELx_EC_MASK, ESR_ELx_EC_SERROR);
+		vcpu_write_sys_reg(vcpu, esr, exception_esr_elx(vcpu));
+		return 1;
+	}
+
+	vcpu_set_vsesr(vcpu, esr & ESR_ELx_ISS_MASK);
+	*vcpu_hcr(vcpu) |= HCR_VSE;
+	return 1;
 }