[PATCH 04/28] KVM: arm64: Drop __HCRX_EL2_* masks

Marc Zyngier maz at kernel.org
Thu Jul 2 09:02:24 PDT 2026


The __HCRX_EL2_* masks are a leftover from a time where we didn't
have much sanitisation for the system registers. Since we are now
in a better place, rely on the existing checks to detect unhandled
bits in HCRX_EL2.

Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/include/asm/kvm_arm.h | 15 ---------------
 arch/arm64/kvm/config.c          |  3 +--
 arch/arm64/kvm/emulate-nested.c  |  5 -----
 3 files changed, 1 insertion(+), 22 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 3f9233b5a1308..f6cd851047947 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -287,21 +287,6 @@
 				 GENMASK(19, 18) |	\
 				 GENMASK(15, 0))
 
-/*
- * Polarity masks for HCRX_EL2, limited to the bits that we know about
- * at this point in time. It doesn't mean that we actually *handle*
- * them, but that at least those that are not advertised to a guest
- * will be RES0 for that guest.
- */
-#define __HCRX_EL2_MASK		(BIT_ULL(6))
-#define __HCRX_EL2_nMASK	(GENMASK_ULL(24, 14) | \
-				 GENMASK_ULL(11, 7)  | \
-				 GENMASK_ULL(5, 0))
-#define __HCRX_EL2_RES0		~(__HCRX_EL2_nMASK | __HCRX_EL2_MASK)
-#define __HCRX_EL2_RES1		~(__HCRX_EL2_nMASK | \
-				  __HCRX_EL2_MASK  | \
-				  __HCRX_EL2_RES0)
-
 /* Hyp Prefetch Fault Address Register (HPFAR/HDFAR) */
 #define HPFAR_MASK	(~UL(0xf))
 /*
diff --git a/arch/arm64/kvm/config.c b/arch/arm64/kvm/config.c
index 0622162b089e5..16d8148dc3f12 100644
--- a/arch/arm64/kvm/config.c
+++ b/arch/arm64/kvm/config.c
@@ -933,7 +933,7 @@ static const struct reg_bits_to_feat_map hcrx_feat_map[] = {
 };
 
 
-static const DECLARE_FEAT_MAP(hcrx_desc, __HCRX_EL2,
+static const DECLARE_FEAT_MAP(hcrx_desc, HCRX_EL2,
 			      hcrx_feat_map, FEAT_HCX);
 
 static const struct reg_bits_to_feat_map hcr_feat_map[] = {
@@ -1579,7 +1579,6 @@ struct resx get_reg_fixed_bits(struct kvm *kvm, enum vcpu_sysreg reg)
 		break;
 	case HCRX_EL2:
 		resx = compute_reg_resx_bits(kvm, &hcrx_desc, 0, 0);
-		resx.res1 |= __HCRX_EL2_RES1;
 		break;
 	case HCR_EL2:
 		resx = compute_reg_resx_bits(kvm, &hcr_desc, 0, 0);
diff --git a/arch/arm64/kvm/emulate-nested.c b/arch/arm64/kvm/emulate-nested.c
index 3c82f392845d1..b7f3d86a94031 100644
--- a/arch/arm64/kvm/emulate-nested.c
+++ b/arch/arm64/kvm/emulate-nested.c
@@ -2320,7 +2320,6 @@ int __init populate_nv_trap_config(void)
 	BUILD_BUG_ON(__NR_CGT_GROUP_IDS__ > BIT(TC_CGT_BITS));
 	BUILD_BUG_ON(__NR_FGT_GROUP_IDS__ > BIT(TC_FGT_BITS));
 	BUILD_BUG_ON(__NR_FG_FILTER_IDS__ > BIT(TC_FGF_BITS));
-	BUILD_BUG_ON(__HCRX_EL2_MASK & __HCRX_EL2_nMASK);
 
 	for (int i = 0; i < ARRAY_SIZE(encoding_to_cgt); i++) {
 		const struct encoding_to_trap_config *cgt = &encoding_to_cgt[i];
@@ -2346,10 +2345,6 @@ int __init populate_nv_trap_config(void)
 		}
 	}
 
-	if (__HCRX_EL2_RES0 != HCRX_EL2_RES0)
-		kvm_info("Sanitised HCR_EL2_RES0 = %016llx, expecting %016llx\n",
-			 __HCRX_EL2_RES0, HCRX_EL2_RES0);
-
 	kvm_info("nv: %ld coarse grained trap handlers\n",
 		 ARRAY_SIZE(encoding_to_cgt));
 
-- 
2.47.3




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