public inbox for linux-arm-kernel@lists.infradead.org
 help / color / mirror / Atom feed
From: Marc Zyngier <maz@kernel.org>
To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org,
	kvm@vger.kernel.org
Cc: Joey Gouly <joey.gouly@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Oliver Upton <oupton@kernel.org>,
	Zenghui Yu <yuzenghui@huawei.com>, Fuad Tabba <tabba@google.com>,
	Will Deacon <will@kernel.org>,
	Catalin Marinas <catalin.marinas@arm.com>
Subject: [PATCH 11/20] KVM: arm64: Add REQUIRES_E2H1 constraint as configuration flags
Date: Mon, 26 Jan 2026 12:16:45 +0000	[thread overview]
Message-ID: <20260126121655.1641736-12-maz@kernel.org> (raw)
In-Reply-To: <20260126121655.1641736-1-maz@kernel.org>

A bunch of EL2 configuration are very similar to their EL1 counterpart,
with the added constraint that HCR_EL2.E2H being 1.

For us, this means HCR_EL2.E2H being RES1, which is something we can
statically evaluate.

Add a REQUIRES_E2H1 constraint, which allows us to express conditions
in a much simpler way (without extra code). Existing occurrences are
converted, before we add a lot more.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/config.c | 38 ++++++++++++++------------------------
 1 file changed, 14 insertions(+), 24 deletions(-)

diff --git a/arch/arm64/kvm/config.c b/arch/arm64/kvm/config.c
index 4fac04d3132c0..1990cebc77c66 100644
--- a/arch/arm64/kvm/config.c
+++ b/arch/arm64/kvm/config.c
@@ -25,6 +25,7 @@ struct reg_bits_to_feat_map {
 #define	FIXED_VALUE	BIT(2)	/* RAZ/WI or RAO/WI in KVM */
 #define	MASKS_POINTER	BIT(3)	/* Pointer to fgt_masks struct instead of bits */
 #define	AS_RES1		BIT(4)	/* RES1 when not supported */
+#define	REQUIRES_E2H1	BIT(5)	/* Add HCR_EL2.E2H RES1 as a pre-condition */
 
 	unsigned long	flags;
 
@@ -311,21 +312,6 @@ static bool feat_trbe_mpam(struct kvm *kvm)
 		(read_sysreg_s(SYS_TRBIDR_EL1) & TRBIDR_EL1_MPAM));
 }
 
-static bool feat_asid2_e2h1(struct kvm *kvm)
-{
-	return kvm_has_feat(kvm, FEAT_ASID2) && !kvm_has_feat(kvm, FEAT_E2H0);
-}
-
-static bool feat_d128_e2h1(struct kvm *kvm)
-{
-	return kvm_has_feat(kvm, FEAT_D128) && !kvm_has_feat(kvm, FEAT_E2H0);
-}
-
-static bool feat_mec_e2h1(struct kvm *kvm)
-{
-	return kvm_has_feat(kvm, FEAT_MEC) && !kvm_has_feat(kvm, FEAT_E2H0);
-}
-
 static bool feat_ebep_pmuv3_ss(struct kvm *kvm)
 {
 	return kvm_has_feat(kvm, FEAT_EBEP) || kvm_has_feat(kvm, FEAT_PMUv3_SS);
@@ -1045,15 +1031,15 @@ static const DECLARE_FEAT_MAP(sctlr2_desc, SCTLR2_EL1,
 			      sctlr2_feat_map, FEAT_SCTLR2);
 
 static const struct reg_bits_to_feat_map tcr2_el2_feat_map[] = {
-	NEEDS_FEAT(TCR2_EL2_FNG1	|
-		   TCR2_EL2_FNG0	|
-		   TCR2_EL2_A2,
-		   feat_asid2_e2h1),
-	NEEDS_FEAT(TCR2_EL2_DisCH1	|
-		   TCR2_EL2_DisCH0	|
-		   TCR2_EL2_D128,
-		   feat_d128_e2h1),
-	NEEDS_FEAT(TCR2_EL2_AMEC1, feat_mec_e2h1),
+	NEEDS_FEAT_FLAG(TCR2_EL2_FNG1	|
+			TCR2_EL2_FNG0	|
+			TCR2_EL2_A2,
+			REQUIRES_E2H1, FEAT_ASID2),
+	NEEDS_FEAT_FLAG(TCR2_EL2_DisCH1	|
+			TCR2_EL2_DisCH0	|
+			TCR2_EL2_D128,
+			REQUIRES_E2H1, FEAT_D128),
+	NEEDS_FEAT_FLAG(TCR2_EL2_AMEC1, REQUIRES_E2H1, FEAT_MEC),
 	NEEDS_FEAT(TCR2_EL2_AMEC0, FEAT_MEC),
 	NEEDS_FEAT(TCR2_EL2_HAFT, FEAT_HAFT),
 	NEEDS_FEAT(TCR2_EL2_PTTWI	|
@@ -1285,6 +1271,7 @@ struct resx compute_resx_bits(struct kvm *kvm,
 			      unsigned long require,
 			      unsigned long exclude)
 {
+	bool e2h0 = kvm_has_feat(kvm, FEAT_E2H0);
 	struct resx resx = {};
 
 	for (int i = 0; i < map_size; i++) {
@@ -1307,6 +1294,9 @@ struct resx compute_resx_bits(struct kvm *kvm,
 			match = idreg_feat_match(kvm, &map[i]);
 		}
 
+		if (map[i].flags & REQUIRES_E2H1)
+			match &= !e2h0;
+		
 		if (!match) {
 			if (map[i].flags & AS_RES1)
  				resx.res1 |= reg_feat_map_bits(&map[i]);
-- 
2.47.3



  parent reply	other threads:[~2026-01-26 12:18 UTC|newest]

Thread overview: 53+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-01-26 12:16 [PATCH 00/20] KVM: arm64: Generalise RESx handling Marc Zyngier
2026-01-26 12:16 ` [PATCH 01/20] arm64: Convert SCTLR_EL2 to sysreg infrastructure Marc Zyngier
2026-01-26 17:53   ` Fuad Tabba
2026-01-26 12:16 ` [PATCH 02/20] KVM: arm64: Remove duplicate configuration for SCTLR_EL1.{EE,E0E} Marc Zyngier
2026-01-26 18:04   ` Fuad Tabba
2026-01-26 12:16 ` [PATCH 03/20] KVM: arm64: Introduce standalone FGU computing primitive Marc Zyngier
2026-01-26 18:35   ` Fuad Tabba
2026-01-26 12:16 ` [PATCH 04/20] KVM: arm64: Introduce data structure tracking both RES0 and RES1 bits Marc Zyngier
2026-01-26 18:54   ` Fuad Tabba
2026-01-26 12:16 ` [PATCH 05/20] KVM: arm64: Extend unified RESx handling to runtime sanitisation Marc Zyngier
2026-01-26 19:15   ` Fuad Tabba
2026-01-27 10:52     ` Marc Zyngier
2026-01-26 12:16 ` [PATCH 06/20] KVM: arm64: Inherit RESx bits from FGT register descriptors Marc Zyngier
2026-01-27 15:21   ` Joey Gouly
2026-01-27 17:58   ` Fuad Tabba
2026-01-26 12:16 ` [PATCH 07/20] KVM: arm64: Allow RES1 bits to be inferred from configuration Marc Zyngier
2026-01-27 15:26   ` Joey Gouly
2026-01-27 17:58   ` Fuad Tabba
2026-01-26 12:16 ` [PATCH 08/20] KVM: arm64: Correctly handle SCTLR_EL1 RES1 bits for unsupported features Marc Zyngier
2026-01-27 18:06   ` Fuad Tabba
2026-01-26 12:16 ` [PATCH 09/20] KVM: arm64: Convert HCR_EL2.RW to AS_RES1 Marc Zyngier
2026-01-27 18:09   ` Fuad Tabba
2026-01-26 12:16 ` [PATCH 10/20] KVM: arm64: Simplify FIXED_VALUE handling Marc Zyngier
2026-01-27 18:20   ` Fuad Tabba
2026-01-26 12:16 ` Marc Zyngier [this message]
2026-01-27 18:28   ` [PATCH 11/20] KVM: arm64: Add REQUIRES_E2H1 constraint as configuration flags Fuad Tabba
2026-01-26 12:16 ` [PATCH 12/20] KVM: arm64: Add RESx_WHEN_E2Hx constraints " Marc Zyngier
2026-01-28 17:43   ` Fuad Tabba
2026-01-29 10:14     ` Marc Zyngier
2026-01-29 10:30       ` Fuad Tabba
2026-01-26 12:16 ` [PATCH 13/20] KVM: arm64: Move RESx into individual register descriptors Marc Zyngier
2026-01-29 16:29   ` Fuad Tabba
2026-01-29 17:19     ` Marc Zyngier
2026-01-29 17:39       ` Fuad Tabba
2026-01-29 18:07       ` Marc Zyngier
2026-01-29 18:13         ` Fuad Tabba
2026-01-30  9:06           ` Marc Zyngier
2026-01-26 12:16 ` [PATCH 14/20] KVM: arm64: Simplify handling of HCR_EL2.E2H RESx Marc Zyngier
2026-01-29 16:41   ` Fuad Tabba
2026-01-26 12:16 ` [PATCH 15/20] KVM: arm64: Get rid of FIXED_VALUE altogether Marc Zyngier
2026-01-29 16:54   ` Fuad Tabba
2026-01-26 12:16 ` [PATCH 16/20] KVM: arm64: Simplify handling of full register invalid constraint Marc Zyngier
2026-01-29 17:34   ` Fuad Tabba
2026-01-26 12:16 ` [PATCH 17/20] KVM: arm64: Remove all traces of FEAT_TME Marc Zyngier
2026-01-29 17:43   ` Fuad Tabba
2026-01-26 12:16 ` [PATCH 18/20] KVM: arm64: Remove all traces of HCR_EL2.MIOCNCE Marc Zyngier
2026-01-29 17:51   ` Fuad Tabba
2026-01-26 12:16 ` [PATCH 19/20] KVM: arm64: Add sanitisation to SCTLR_EL2 Marc Zyngier
2026-01-29 18:11   ` Fuad Tabba
2026-01-26 12:16 ` [PATCH 20/20] KVM: arm64: Add debugfs file dumping computed RESx values Marc Zyngier
2026-02-02  8:59   ` Fuad Tabba
2026-02-02  9:14     ` Marc Zyngier
2026-02-02  9:57       ` Fuad Tabba

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20260126121655.1641736-12-maz@kernel.org \
    --to=maz@kernel.org \
    --cc=catalin.marinas@arm.com \
    --cc=joey.gouly@arm.com \
    --cc=kvm@vger.kernel.org \
    --cc=kvmarm@lists.linux.dev \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=oupton@kernel.org \
    --cc=suzuki.poulose@arm.com \
    --cc=tabba@google.com \
    --cc=will@kernel.org \
    --cc=yuzenghui@huawei.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox