Subject: [PATCH v10 44/59] KVM: arm64: nv: Add handling of FEAT_TTL TLB invalidation

From: Marc Zyngier <[email-masked]>
Date: Mon, 15 May 2023 18:30:48 +0100

Support guest-provided information information to find out about
the range of required invalidation.

Signed-off-by: Marc Zyngier <[email-masked]>
---
 arch/arm64/include/asm/kvm_nested.h |  2 +
 arch/arm64/kvm/nested.c             | 90 +++++++++++++++++++++++++++++
 arch/arm64/kvm/sys_regs.c           | 26 +--------
 3 files changed, 93 insertions(+), 25 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h
index f7aa32cc2a72..d203263334e1 100644
--- a/arch/arm64/include/asm/kvm_nested.h
+++ b/arch/arm64/include/asm/kvm_nested.h
@@ -127,6 +127,8 @@ int handle_wfx_nested(struct kvm_vcpu *vcpu, bool is_wfe);
 extern bool forward_smc_trap(struct kvm_vcpu *vcpu);
 extern bool __check_nv_sr_forward(struct kvm_vcpu *vcpu);
 
+unsigned long compute_tlb_inval_range(struct kvm_s2_mmu *mmu, u64 val);
+
 struct sys_reg_params;
 struct sys_reg_desc;
 
diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index a01ed0e1db82..4bb845f75725 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -354,6 +354,96 @@ int kvm_walk_nested_s2(struct kvm_vcpu *vcpu, phys_addr_t gipa,
 	return ret;
 }
 
+static unsigned int ttl_to_size(u8 ttl)
+{
+	int level = ttl & 3;
+	int gran = (ttl >> 2) & 3;
+	unsigned int max_size = 0;
+
+	switch (gran) {
+	case TLBI_TTL_TG_4K:
+		switch (level) {
+		case 0:
+			break;
+		case 1:
+			max_size = SZ_1G;
+			break;
+		case 2:
+			max_size = SZ_2M;
+			break;
+		case 3:
+			max_size = SZ_4K;
+			break;
+		}
+		break;
+	case TLBI_TTL_TG_16K:
+		switch (level) {
+		case 0:
+		case 1:
+			break;
+		case 2:
+			max_size = SZ_32M;
+			break;
+		case 3:
+			max_size = SZ_16K;
+			break;
+		}
+		break;
+	case TLBI_TTL_TG_64K:
+		switch (level) {
+		case 0:
+		case 1:
+			/* No 52bit IPA support */
+			break;
+		case 2:
+			max_size = SZ_512M;
+			break;
+		case 3:
+			max_size = SZ_64K;
+			break;
+		}
+		break;
+	default:			/* No size information */
+		break;
+	}
+
+	return max_size;
+}
+
+unsigned long compute_tlb_inval_range(struct kvm_s2_mmu *mmu, u64 val)
+{
+	unsigned long max_size;
+	u8 ttl;
+
+	ttl = FIELD_GET(GENMASK_ULL(47, 44), val);
+
+	max_size = ttl_to_size(ttl);
+
+	if (!max_size) {
+		/* Compute the maximum extent of the invalidation */
+		switch (mmu->tlb_vtcr & VTCR_EL2_TG0_MASK) {
+		case VTCR_EL2_TG0_4K:
+			max_size = SZ_1G;
+			break;
+		case VTCR_EL2_TG0_16K:
+			max_size = SZ_32M;
+			break;
+		case VTCR_EL2_TG0_64K:
+			/*
+			 * No, we do not support 52bit IPA in nested yet. Once
+			 * we do, this should be 4TB.
+			 */
+			max_size = SZ_512M;
+			break;
+		default:
+			BUG();
+		}
+	}
+
+	WARN_ON(!max_size);
+	return max_size;
+}
+
 /*
  * We can have multiple *different* MMU contexts with the same VMID:
  *
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index ce65a21f618d..3c2fe3fd9ab3 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2916,36 +2916,12 @@ static void s2_mmu_unmap_stage2_ipa(struct kvm_s2_mmu *mmu,
 	 *
 	 * - NS bit: we're non-secure only.
 	 *
-	 * - TTL field: We already have the granule size from the
-	 *   VTCR_EL2.TG0 field, and the level is only relevant to the
-	 *   guest's S2PT.
-	 *
 	 * - IPA[51:48]: We don't support 52bit IPA just yet...
 	 *
 	 * And of course, adjust the IPA to be on an actual address.
 	 */
 	base_addr = (info->ipa.addr & GENMASK_ULL(35, 0)) << 12;
-
-	/* Compute the maximum extent of the invalidation */
-	switch (mmu->tlb_vtcr & VTCR_EL2_TG0_MASK) {
-	case VTCR_EL2_TG0_4K:
-		max_size = SZ_1G;
-		break;
-	case VTCR_EL2_TG0_16K:
-		max_size = SZ_32M;
-		break;
-	case VTCR_EL2_TG0_64K:
-		/*
-		 * No, we do not support 52bit IPA in nested yet. Once
-		 * we do, this should be 4TB.
-		 */
-		/* FIXME: remove the 52bit PA support from the IDregs */
-		max_size = SZ_512M;
-		break;
-	default:
-		BUG();
-	}
-
+	max_size = compute_tlb_inval_range(mmu, info->ipa.addr);
 	base_addr &= ~(max_size - 1);
 
 	kvm_unmap_stage2_range(mmu, base_addr, max_size);
-- 
2.34.1

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