3 files changed, 61 insertions, 27 deletions

diff --git a/arch/arm64/kvm/hyp/include/hyp/fault.h b/arch/arm64/kvm/hyp/include/hyp/fault.h
index 17df94570f03..fc573fc767b0 100644
--- a/arch/arm64/kvm/hyp/include/hyp/fault.h
+++ b/arch/arm64/kvm/hyp/include/hyp/fault.h
@@ -12,6 +12,16 @@
 #include <asm/kvm_hyp.h>
 #include <asm/kvm_mmu.h>
 
+static inline bool __fault_safe_to_translate(u64 esr)
+{
+	u64 fsc = esr & ESR_ELx_FSC;
+
+	if (esr_fsc_is_sea_ttw(esr) || esr_fsc_is_secc_ttw(esr))
+		return false;
+
+	return !(fsc == ESR_ELx_FSC_EXTABT && (esr & ESR_ELx_FnV));
+}
+
 static inline bool __translate_far_to_hpfar(u64 far, u64 *hpfar)
 {
 	int ret;
@@ -44,34 +54,50 @@ static inline bool __translate_far_to_hpfar(u64 far, u64 *hpfar)
 	return true;
 }
 
-static inline bool __get_fault_info(u64 esr, struct kvm_vcpu_fault_info *fault)
+/*
+ * Checks for the conditions when HPFAR_EL2 is written, per ARM ARM R_FKLWR.
+ */
+static inline bool __hpfar_valid(u64 esr)
 {
-	u64 hpfar, far;
-
-	far = read_sysreg_el2(SYS_FAR);
-
 	/*
-	 * The HPFAR can be invalid if the stage 2 fault did not
-	 * happen during a stage 1 page table walk (the ESR_EL2.S1PTW
-	 * bit is clear) and one of the two following cases are true:
-	 *   1. The fault was due to a permission fault
-	 *   2. The processor carries errata 834220
+	 * CPUs affected by ARM erratum #834220 may incorrectly report a
+	 * stage-2 translation fault when a stage-1 permission fault occurs.
 	 *
-	 * Therefore, for all non S1PTW faults where we either have a
-	 * permission fault or the errata workaround is enabled, we
-	 * resolve the IPA using the AT instruction.
+	 * Re-walk the page tables to determine if a stage-1 fault actually
+	 * occurred.
 	 */
-	if (!(esr & ESR_ELx_S1PTW) &&
-	    (cpus_have_final_cap(ARM64_WORKAROUND_834220) ||
-	     esr_fsc_is_permission_fault(esr))) {
-		if (!__translate_far_to_hpfar(far, &hpfar))
-			return false;
-	} else {
+	if (cpus_have_final_cap(ARM64_WORKAROUND_834220) &&
+	    esr_fsc_is_translation_fault(esr))
+		return false;
+
+	if (esr_fsc_is_translation_fault(esr) || esr_fsc_is_access_flag_fault(esr))
+		return true;
+
+	if ((esr & ESR_ELx_S1PTW) && esr_fsc_is_permission_fault(esr))
+		return true;
+
+	return esr_fsc_is_addr_sz_fault(esr);
+}
+
+static inline bool __get_fault_info(u64 esr, struct kvm_vcpu_fault_info *fault)
+{
+	u64 hpfar;
+
+	fault->far_el2		= read_sysreg_el2(SYS_FAR);
+	fault->hpfar_el2	= 0;
+
+	if (__hpfar_valid(esr))
 		hpfar = read_sysreg(hpfar_el2);
-	}
+	else if (unlikely(!__fault_safe_to_translate(esr)))
+		return true;
+	else if (!__translate_far_to_hpfar(fault->far_el2, &hpfar))
+		return false;
 
-	fault->far_el2 = far;
-	fault->hpfar_el2 = hpfar;
+	/*
+	 * Hijack HPFAR_EL2.NS (RES0 in Non-secure) to indicate a valid
+	 * HPFAR value.
+	 */
+	fault->hpfar_el2 = hpfar | HPFAR_EL2_NS;
 	return true;
 }
 
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index e433dfab882a..3369dd0c4009 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -730,10 +730,10 @@ static void do_ffa_version(struct arm_smccc_res *res,
 		hyp_ffa_version = ffa_req_version;
 	}
 
-	if (hyp_ffa_post_init())
+	if (hyp_ffa_post_init()) {
 		res->a0 = FFA_RET_NOT_SUPPORTED;
-	else {
-		has_version_negotiated = true;
+	} else {
+		smp_store_release(&has_version_negotiated, true);
 		res->a0 = hyp_ffa_version;
 	}
 unlock:
@@ -809,7 +809,8 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt, u32 func_id)
 	if (!is_ffa_call(func_id))
 		return false;
 
-	if (!has_version_negotiated && func_id != FFA_VERSION) {
+	if (func_id != FFA_VERSION &&
+	    !smp_load_acquire(&has_version_negotiated)) {
 		ffa_to_smccc_error(&res, FFA_RET_INVALID_PARAMETERS);
 		goto out_handled;
 	}
diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index f34f11c720d7..2a5284f749b4 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -578,7 +578,14 @@ void handle_host_mem_abort(struct kvm_cpu_context *host_ctxt)
 		return;
 	}
 
-	addr = (fault.hpfar_el2 & HPFAR_MASK) << 8;
+
+	/*
+	 * Yikes, we couldn't resolve the fault IPA. This should reinject an
+	 * abort into the host when we figure out how to do that.
+	 */
+	BUG_ON(!(fault.hpfar_el2 & HPFAR_EL2_NS));
+	addr = FIELD_GET(HPFAR_EL2_FIPA, fault.hpfar_el2) << 12;
+
 	ret = host_stage2_idmap(addr);
 	BUG_ON(ret && ret != -EAGAIN);
 }