Commit 2ac638fc authored by Catalin Marinas's avatar Catalin Marinas
Browse files

arm64: kvm: mte: Hide the MTE CPUID information from the guests 



KVM does not support MTE in guests yet, so clear the corresponding field
in the ID_AA64PFR1_EL1 register. In addition, inject an undefined
exception in the guest if it accesses one of the GCR_EL1, RGSR_EL1,
TFSR_EL1 or TFSRE0_EL1 registers. While the emulate_sys_reg() function
already injects an undefined exception, this patch prevents the
unnecessary printk.

Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Cc: Steven Price <steven.price@arm.com>
Acked-by: default avatarMarc Zyngier <maz@kernel.org>
parent 3b714d24

arch/arm64/kvm/sys_regs.c

+16 −0
Original line number Diff line number Diff line
@@ -1131,6 +1131,8 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu, 
		if (!vcpu_has_sve(vcpu))

			val &= ~(0xfUL << ID_AA64PFR0_SVE_SHIFT);

		val &= ~(0xfUL << ID_AA64PFR0_AMU_SHIFT);

	} else if (id == SYS_ID_AA64PFR1_EL1) {

		val &= ~(0xfUL << ID_AA64PFR1_MTE_SHIFT);

	} else if (id == SYS_ID_AA64ISAR1_EL1 && !vcpu_has_ptrauth(vcpu)) {

		val &= ~((0xfUL << ID_AA64ISAR1_APA_SHIFT) |

			 (0xfUL << ID_AA64ISAR1_API_SHIFT) |
@@ -1382,6 +1384,13 @@ static bool access_ccsidr(struct kvm_vcpu *vcpu, struct sys_reg_params *p, 
	return true;

}



static bool access_mte_regs(struct kvm_vcpu *vcpu, struct sys_reg_params *p,

			    const struct sys_reg_desc *r)

{

	kvm_inject_undefined(vcpu);

	return false;

}



/* sys_reg_desc initialiser for known cpufeature ID registers */

#define ID_SANITISED(name) {			\

	SYS_DESC(SYS_##name),			\
@@ -1547,6 +1556,10 @@ static const struct sys_reg_desc sys_reg_descs[] = { 
	{ SYS_DESC(SYS_SCTLR_EL1), access_vm_reg, reset_val, SCTLR_EL1, 0x00C50078 },

	{ SYS_DESC(SYS_ACTLR_EL1), access_actlr, reset_actlr, ACTLR_EL1 },

	{ SYS_DESC(SYS_CPACR_EL1), NULL, reset_val, CPACR_EL1, 0 },



	{ SYS_DESC(SYS_RGSR_EL1), access_mte_regs },

	{ SYS_DESC(SYS_GCR_EL1), access_mte_regs },



	{ SYS_DESC(SYS_ZCR_EL1), NULL, reset_val, ZCR_EL1, 0, .visibility = sve_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 },
@@ -1571,6 +1584,9 @@ static const struct sys_reg_desc sys_reg_descs[] = { 
	{ SYS_DESC(SYS_ERXMISC0_EL1), trap_raz_wi },

	{ SYS_DESC(SYS_ERXMISC1_EL1), trap_raz_wi },



	{ SYS_DESC(SYS_TFSR_EL1), access_mte_regs },

	{ SYS_DESC(SYS_TFSRE0_EL1), access_mte_regs },



	{ SYS_DESC(SYS_FAR_EL1), access_vm_reg, reset_unknown, FAR_EL1 },

	{ SYS_DESC(SYS_PAR_EL1), NULL, reset_unknown, PAR_EL1 },

CRA Git | Maintained and supported by SUSTech CRA and CCSE