Merge tag 'kvmarm-fixes-6.13-2' of https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.13, part #2

 - Fix confusion with implicitly-shifted MDCR_EL2 masks breaking
   SPE/TRBE initialization

 - Align nested page table walker with the intended memory attribute
   combining rules of the architecture

 - Prevent userspace from constraining the advertised ASID width,
   avoiding horrors of guest TLBIs not matching the intended context in
   hardware

 - Don't leak references on LPIs when insertion into the translation
   cache fails

Author: bonzini

arch/arm64/include/asm/el2_setup.h

@@ -87,7 +87,7 @@
 		      1 << PMSCR_EL2_PA_SHIFT)
 	msr_s	SYS_PMSCR_EL2, x0		// addresses and physical counter
 .Lskip_spe_el2_\@:
-	mov	x0, #(MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT)
+	mov	x0, #MDCR_EL2_E2PB_MASK
 	orr	x2, x2, x0			// If we don't have VHE, then
 						// use EL1&0 translation.
 
@@ -100,7 +100,7 @@
 	and	x0, x0, TRBIDR_EL1_P
 	cbnz	x0, .Lskip_trace_\@		// If TRBE is available at EL2
 
-	mov	x0, #(MDCR_EL2_E2TB_MASK << MDCR_EL2_E2TB_SHIFT)
+	mov	x0, #MDCR_EL2_E2TB_MASK
 	orr	x2, x2, x0			// allow the EL1&0 translation
 						// to own it.
 

arch/arm64/kernel/hyp-stub.S

@@ -114,8 +114,8 @@ SYM_CODE_START_LOCAL(__finalise_el2)
 
 	// Use EL2 translations for SPE & TRBE and disable access from EL1
 	mrs	x0, mdcr_el2
-	bic	x0, x0, #(MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT)
-	bic	x0, x0, #(MDCR_EL2_E2TB_MASK << MDCR_EL2_E2TB_SHIFT)
+	bic	x0, x0, #MDCR_EL2_E2PB_MASK
+	bic	x0, x0, #MDCR_EL2_E2TB_MASK
 	msr	mdcr_el2, x0
 
 	// Transfer the MM state from EL1 to EL2

arch/arm64/kvm/at.c

@@ -739,8 +739,15 @@ static u64 compute_par_s12(struct kvm_vcpu *vcpu, u64 s1_par,
 			final_attr = s1_parattr;
 			break;
 		default:
-			/* MemAttr[2]=0, Device from S2 */
-			final_attr = s2_memattr & GENMASK(1,0) << 2;
+			/*
+			 * MemAttr[2]=0, Device from S2.
+			 *
+			 * FWB does not influence the way that stage 1
+			 * memory types and attributes are combined
+			 * with stage 2 Device type and attributes.
+			 */
+			final_attr = min(s2_memattr_to_attr(s2_memattr),
+					 s1_parattr);
 		}
 	} else {
 		/* Combination of R_HMNDG, R_TNHFM and R_GQFSF */

arch/arm64/kvm/hyp/nvhe/pkvm.c

@@ -126,7 +126,7 @@ static void pvm_init_traps_aa64dfr0(struct kvm_vcpu *vcpu)
 	/* Trap SPE */
 	if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMSVer), feature_ids)) {
 		mdcr_set |= MDCR_EL2_TPMS;
-		mdcr_clear |= MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT;
+		mdcr_clear |= MDCR_EL2_E2PB_MASK;
 	}
 
 	/* Trap Trace Filter */
@@ -143,7 +143,7 @@ static void pvm_init_traps_aa64dfr0(struct kvm_vcpu *vcpu)
 
 	/* Trap External Trace */
 	if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_ExtTrcBuff), feature_ids))
-		mdcr_clear |= MDCR_EL2_E2TB_MASK << MDCR_EL2_E2TB_SHIFT;
+		mdcr_clear |= MDCR_EL2_E2TB_MASK;
 
 	vcpu->arch.mdcr_el2 |= mdcr_set;
 	vcpu->arch.mdcr_el2 &= ~mdcr_clear;

arch/arm64/kvm/sys_regs.c

@@ -2618,7 +2618,8 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	ID_WRITABLE(ID_AA64MMFR0_EL1, ~(ID_AA64MMFR0_EL1_RES0 |
 					ID_AA64MMFR0_EL1_TGRAN4_2 |
 					ID_AA64MMFR0_EL1_TGRAN64_2 |
-					ID_AA64MMFR0_EL1_TGRAN16_2)),
+					ID_AA64MMFR0_EL1_TGRAN16_2 |
+					ID_AA64MMFR0_EL1_ASIDBITS)),
 	ID_WRITABLE(ID_AA64MMFR1_EL1, ~(ID_AA64MMFR1_EL1_RES0 |
 					ID_AA64MMFR1_EL1_HCX |
 					ID_AA64MMFR1_EL1_TWED |

arch/arm64/kvm/vgic/vgic-its.c

@@ -608,12 +608,22 @@ static void vgic_its_cache_translation(struct kvm *kvm, struct vgic_its *its,
 	lockdep_assert_held(&its->its_lock);
 	vgic_get_irq_kref(irq);
 
+	old = xa_store(&its->translation_cache, cache_key, irq, GFP_KERNEL_ACCOUNT);
+
+	/*
+	 * Put the reference taken on @irq if the store fails. Intentionally do
+	 * not return the error as the translation cache is best effort.
+	 */
+	if (xa_is_err(old)) {
+		vgic_put_irq(kvm, irq);
+		return;
+	}
+
 	/*
 	 * We could have raced with another CPU caching the same
 	 * translation behind our back, ensure we don't leak a
 	 * reference if that is the case.
 	 */
-	old = xa_store(&its->translation_cache, cache_key, irq, GFP_KERNEL_ACCOUNT);
 	if (old)
 		vgic_put_irq(kvm, old);
 }