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From: Marc Zyngier <maz@kernel.org>
To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org,
	kvm@vger.kernel.org
Cc: Steffen Eiden <seiden@linux.ibm.com>,
	Joey Gouly <joey.gouly@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Oliver Upton <oupton@kernel.org>,
	Zenghui Yu <yuzenghui@huawei.com>
Subject: [PATCH v2 22/28] KVM: arm64: Add routing for NVHCR_EL2 trap
Date: Tue, 14 Jul 2026 10:16:35 +0100	[thread overview]
Message-ID: <20260714091641.1970822-23-maz@kernel.org> (raw)
In-Reply-To: <20260714091641.1970822-1-maz@kernel.org>

NVHCR_EL2 accesses from EL1 are taken to EL2 when HCRX_EL2.NVTGE==0
and HCR_EL2.NV==1. Describe this in the exception routing tables.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/emulate-nested.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/arch/arm64/kvm/emulate-nested.c b/arch/arm64/kvm/emulate-nested.c
index b7f3d86a94031..625604019fb32 100644
--- a/arch/arm64/kvm/emulate-nested.c
+++ b/arch/arm64/kvm/emulate-nested.c
@@ -136,6 +136,8 @@ enum cgt_group_id {
 	CGT_CPTR_TTA,
 	CGT_MDCR_HPMN,
 
+	CGT_HCR_NV_HCRX_nNVTGE,
+
 	/* Must be last */
 	__NR_CGT_GROUP_IDS__
 };
@@ -588,6 +590,15 @@ static enum trap_behaviour check_mdcr_hpmn(struct kvm_vcpu *vcpu)
 	return BEHAVE_HANDLE_LOCALLY;
 }
 
+static enum trap_behaviour check_hcr_nv_hcrx_nnvtge(struct kvm_vcpu *vcpu)
+{
+	if ((__vcpu_sys_reg(vcpu, HCR_EL2) & HCR_EL2_NV) &&
+	    !(__vcpu_sys_reg(vcpu, HCRX_EL2) & HCRX_EL2_NVTGE))
+		return BEHAVE_FORWARD_RW;
+
+	return BEHAVE_HANDLE_LOCALLY;
+}
+
 #define CCC(id, fn)				\
 	[id - __COMPLEX_CONDITIONS__] = fn
 
@@ -598,6 +609,7 @@ static const complex_condition_check ccc[] = {
 	CCC(CGT_CNTHCTL_EL1NVVCT, check_cnthctl_el1nvvct),
 	CCC(CGT_CPTR_TTA, check_cptr_tta),
 	CCC(CGT_MDCR_HPMN, check_mdcr_hpmn),
+	CCC(CGT_HCR_NV_HCRX_nNVTGE, check_hcr_nv_hcrx_nnvtge),
 };
 
 /*
@@ -853,6 +865,7 @@ static const struct encoding_to_trap_config encoding_to_cgt[] __initconst = {
 	SR_TRAP(SYS_SCTLR2_EL2,		CGT_HCR_NV),
 	SR_RANGE_TRAP(SYS_HCR_EL2,
 		      SYS_HCRX_EL2,	CGT_HCR_NV),
+	SR_TRAP(SYS_NVHCR_EL2,		CGT_HCR_NV_HCRX_nNVTGE),
 	SR_TRAP(SYS_SMPRIMAP_EL2,	CGT_HCR_NV),
 	SR_TRAP(SYS_SMCR_EL2,		CGT_HCR_NV),
 	SR_RANGE_TRAP(SYS_TTBR0_EL2,
-- 
2.47.3


  parent reply	other threads:[~2026-07-14  9:16 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-14  9:16 [PATCH v2 00/28] KVM: arm64: Add support for FEAT_NV2p1 and FEAT_NV3 Marc Zyngier
2026-07-14  9:16 ` [PATCH v2 01/28] arm64: sysreg: Emit RESx/UNKN values for Mapping/Fields definitions Marc Zyngier
2026-07-14  9:16 ` [PATCH v2 02/28] arm64: Update ID_AA64MMFR4_EL1 description to 2026-03 JSON release Marc Zyngier
2026-07-14  9:16 ` [PATCH v2 03/28] KVM: arm64: Merge guest's HCRX_EL2 using NV_HCRX_GUEST_EXCLUDE Marc Zyngier
2026-07-14  9:16 ` [PATCH v2 04/28] KVM: arm64: Drop __HCRX_EL2_* masks Marc Zyngier
2026-07-14  9:16 ` [PATCH v2 05/28] KVM: arm64: Plumb HCRX_EL2.SRMASKEn in HCRX_EL2 sanitisation Marc Zyngier
2026-07-14  9:16 ` [PATCH v2 06/28] KVM: arm64: Classify CPTR_EL2 as a SR_LOC_SPECIAL register Marc Zyngier
2026-07-14  9:16 ` [PATCH v2 07/28] KVM: arm64: Don't evaluate HCR_EL2.NV nor HFGITR_EL2.ERET on ERET fast path Marc Zyngier
2026-07-14  9:16 ` [PATCH v2 08/28] arm64: Add ARM64_HAS_NV2P1 capability Marc Zyngier
2026-07-14  9:16 ` [PATCH v2 09/28] KVM: arm64: Relax CPTR_EL2 handling when FEAT_NV2p1 is present Marc Zyngier
2026-07-14 10:12   ` sashiko-bot
2026-07-14  9:16 ` [PATCH v2 10/28] KVM: arm64: Relax CNTHCTL_EL2 " Marc Zyngier
2026-07-14  9:53   ` sashiko-bot
2026-07-14  9:16 ` [PATCH v2 11/28] KVM: arm64: Expose FEAT_NV2p1 to NV guests Marc Zyngier
2026-07-14  9:16 ` [PATCH v2 12/28] arm64: Add FEAT_NV2p1 detection Marc Zyngier
2026-07-14  9:46   ` sashiko-bot
2026-07-14 11:45     ` Marc Zyngier
2026-07-14  9:16 ` [PATCH v2 13/28] arm64: sysreg: Add NVHCR_EL2 description as a mirror of HCR_EL2 Marc Zyngier
2026-07-14  9:16 ` [PATCH v2 14/28] arm64: sysreg: Add HCRX_EL2 bits related to FEAT_NV3 Marc Zyngier
2026-07-14  9:45   ` sashiko-bot
2026-07-14 13:04     ` Marc Zyngier
2026-07-14  9:16 ` [PATCH v2 15/28] arm64: Add ARM64_HAS_NV3 capability Marc Zyngier
2026-07-14  9:40   ` sashiko-bot
2026-07-14 11:42     ` Marc Zyngier
2026-07-14  9:16 ` [PATCH v2 16/28] KVM: arm64: Split NV-specific exit fixups from the non-NV handling Marc Zyngier
2026-07-14  9:16 ` [PATCH v2 17/28] KVM: arm64: Add NV3 control bits to HCRX_EL2 sanitisation Marc Zyngier
2026-07-14  9:16 ` [PATCH v2 18/28] KVM: arm64: Add kvm_has_nv{2,3}() predicates Marc Zyngier
2026-07-14  9:48   ` sashiko-bot
2026-07-14  9:16 ` [PATCH v2 19/28] KVM: arm64: Make HCR_EL2 a non-VNCR register Marc Zyngier
2026-07-14  9:16 ` [PATCH v2 20/28] KVM: arm64: Add sanitisation for NVHCR_EL2 Marc Zyngier
2026-07-14  9:16 ` [PATCH v2 21/28] KVM: arm64: Add NVHCR_EL2 handling to the sysreg array Marc Zyngier
2026-07-14 10:24   ` sashiko-bot
2026-07-14 12:56     ` Marc Zyngier
2026-07-14  9:16 ` Marc Zyngier [this message]
2026-07-14  9:16 ` [PATCH v2 23/28] KVM: arm64: Add NVHCR_EL2 context switching Marc Zyngier
2026-07-14 10:03   ` sashiko-bot
2026-07-14  9:16 ` [PATCH v2 24/28] KVM: arm64: Engage NV3 ERET trap elision Marc Zyngier
2026-07-14  9:16 ` [PATCH v2 25/28] KVM: arm64: Engage NV3 TLBI " Marc Zyngier
2026-07-14  9:16 ` [PATCH v2 26/28] KVM: arm64: Add FEAT_NV3 detection Marc Zyngier
2026-07-14 10:07   ` sashiko-bot
2026-07-14  9:16 ` [PATCH v2 27/28] KVM: arm64: Expose FEAT_NV3 to guests Marc Zyngier
2026-07-14 10:15   ` sashiko-bot
2026-07-14  9:16 ` [PATCH v2 28/28] arm64: Add override for ID_AA64MMFR4_EL1.NV_frac Marc Zyngier

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