[PATCH RFC v2 09/22] KVM: arm64: Basic SME system register descriptions

From: Mark Brown <broonie@kernel.org>
To: Marc Zyngier <maz@kernel.org>,
	Oliver Upton <oliver.upton@linux.dev>,
	 James Morse <james.morse@arm.com>,
	 Suzuki K Poulose <suzuki.poulose@arm.com>,
	 Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	 Paolo Bonzini <pbonzini@redhat.com>,
	Jonathan Corbet <corbet@lwn.net>,  Shuah Khan <shuah@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev,
	 linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	 linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org,
	 Mark Brown <broonie@kernel.org>
Subject: [PATCH RFC v2 09/22] KVM: arm64: Basic SME system register descriptions
Date: Fri, 22 Dec 2023 16:21:17 +0000	[thread overview]
Message-ID: <20231222-kvm-arm64-sme-v2-9-da226cb180bb@kernel.org> (raw)
In-Reply-To: <20231222-kvm-arm64-sme-v2-0-da226cb180bb@kernel.org>

Set up the basic system register descriptions for the more straightforward
SME registers. All the registers are available from SME 1.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 arch/arm64/include/asm/kvm_host.h |  1 +
 arch/arm64/kvm/sys_regs.c         | 23 +++++++++++++++++++----
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 920f8a1ff901..4be5dda9734d 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -333,6 +333,7 @@ enum vcpu_sysreg {
 	ACTLR_EL1,	/* Auxiliary Control Register */
 	CPACR_EL1,	/* Coprocessor Access Control */
 	ZCR_EL1,	/* SVE Control */
+	SMCR_EL1,	/* SME Control */
 	TTBR0_EL1,	/* Translation Table Base Register 0 */
 	TTBR1_EL1,	/* Translation Table Base Register 1 */
 	TCR_EL1,	/* Translation Control Register */
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 4735e1b37fb3..e6339ca1d8dc 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1404,7 +1404,8 @@ static u64 __kvm_read_sanitised_id_reg(const struct kvm_vcpu *vcpu,
 		if (!kvm_has_mte(vcpu->kvm))
 			val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_MTE);
 
-		val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_SME);
+		if (!vcpu_has_sme(vcpu))
+			val &= ~ID_AA64PFR1_EL1_SME_MASK;
 		break;
 	case SYS_ID_AA64ISAR1_EL1:
 		if (!vcpu_has_ptrauth(vcpu))
@@ -1470,6 +1471,9 @@ static unsigned int id_visibility(const struct kvm_vcpu *vcpu,
 		if (!vcpu_has_sve(vcpu))
 			return REG_RAZ;
 		break;
+	case SYS_ID_AA64SMFR0_EL1:
+		if (!vcpu_has_sme(vcpu))
+			return REG_RAZ;
 	}
 
 	return 0;
@@ -1521,6 +1525,16 @@ static unsigned int sve_visibility(const struct kvm_vcpu *vcpu,
 	return REG_HIDDEN;
 }
 
+/* Visibility overrides for SME-specific control registers */
+static unsigned int sme_visibility(const struct kvm_vcpu *vcpu,
+				   const struct sys_reg_desc *rd)
+{
+	if (vcpu_has_sme(vcpu))
+		return 0;
+
+	return REG_HIDDEN;
+}
+
 static u64 read_sanitised_id_aa64pfr0_el1(struct kvm_vcpu *vcpu,
 					  const struct sys_reg_desc *rd)
 {
@@ -2142,7 +2156,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	ID_UNALLOCATED(4,2),
 	ID_UNALLOCATED(4,3),
 	ID_WRITABLE(ID_AA64ZFR0_EL1, ~ID_AA64ZFR0_EL1_RES0),
-	ID_HIDDEN(ID_AA64SMFR0_EL1),
+	ID_WRITABLE(ID_AA64SMFR0_EL1, ~ID_AA64SMFR0_EL1_RES0),
 	ID_UNALLOCATED(4,6),
 	ID_UNALLOCATED(4,7),
 
@@ -2211,7 +2225,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	{ SYS_DESC(SYS_ZCR_EL1), NULL, reset_val, ZCR_EL1, 0, .visibility = sve_visibility },
 	{ SYS_DESC(SYS_TRFCR_EL1), undef_access },
 	{ SYS_DESC(SYS_SMPRI_EL1), undef_access },
-	{ SYS_DESC(SYS_SMCR_EL1), undef_access },
+	{ SYS_DESC(SYS_SMCR_EL1), NULL, reset_val, SMCR_EL1, 0, .visibility = sme_visibility },
 	{ SYS_DESC(SYS_TTBR0_EL1), access_vm_reg, reset_unknown, TTBR0_EL1 },
 	{ SYS_DESC(SYS_TTBR1_EL1), access_vm_reg, reset_unknown, TTBR1_EL1 },
 	{ SYS_DESC(SYS_TCR_EL1), access_vm_reg, reset_val, TCR_EL1, 0 },
@@ -2306,7 +2320,8 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	{ SYS_DESC(SYS_CLIDR_EL1), access_clidr, reset_clidr, CLIDR_EL1,
 	  .set_user = set_clidr },
 	{ SYS_DESC(SYS_CCSIDR2_EL1), undef_access },
-	{ SYS_DESC(SYS_SMIDR_EL1), undef_access },
+	{ SYS_DESC(SYS_SMIDR_EL1), .access = access_id_reg,
+	  .get_user = get_id_reg, .visibility = sme_visibility },
 	{ SYS_DESC(SYS_CSSELR_EL1), access_csselr, reset_unknown, CSSELR_EL1 },
 	{ SYS_DESC(SYS_CTR_EL0), access_ctr },
 	{ SYS_DESC(SYS_SVCR), undef_access },

-- 
2.30.2

