Commit e2d6c906 authored by Marc Zyngier's avatar Marc Zyngier Committed by Oliver Upton
Browse files

arm64: Add KVM_HVHE capability and has_hvhe() predicate 



Expose a capability keying the hVHE feature as well as a new
predicate testing it. Nothing is so far using it, and nothing
is enabling it yet.

Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20230609162200.2024064-5-maz@kernel.org


Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
parent 0ddc312b

arch/arm64/include/asm/cpufeature.h

+1 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
#define cpu_feature(x)		KERNEL_HWCAP_ ## x



#define ARM64_SW_FEATURE_OVERRIDE_NOKASLR	0

#define ARM64_SW_FEATURE_OVERRIDE_HVHE		4



#ifndef __ASSEMBLY__

arch/arm64/include/asm/virt.h

+8 −0
Original line number Diff line number Diff line
@@ -142,6 +142,14 @@ static __always_inline bool is_protected_kvm_enabled(void) 
		return cpus_have_final_cap(ARM64_KVM_PROTECTED_MODE);

}



static __always_inline bool has_hvhe(void)

{

	if (is_vhe_hyp_code())

		return false;



	return cpus_have_final_cap(ARM64_KVM_HVHE);

}



static inline bool is_hyp_nvhe(void)

{

	return is_hyp_mode_available() && !is_kernel_in_hyp_mode();

arch/arm64/kernel/cpufeature.c

+19 −0
Original line number Diff line number Diff line
@@ -1998,6 +1998,19 @@ static bool has_nested_virt_support(const struct arm64_cpu_capabilities *cap, 
	return true;

}



static bool hvhe_possible(const struct arm64_cpu_capabilities *entry,

			  int __unused)

{

	u64 val;



	val = read_sysreg(id_aa64mmfr1_el1);

	if (!cpuid_feature_extract_unsigned_field(val, ID_AA64MMFR1_EL1_VH_SHIFT))

		return false;



	val = arm64_sw_feature_override.val & arm64_sw_feature_override.mask;

	return cpuid_feature_extract_unsigned_field(val, ARM64_SW_FEATURE_OVERRIDE_HVHE);

}



#ifdef CONFIG_ARM64_PAN

static void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused)

{
@@ -2643,6 +2656,12 @@ static const struct arm64_cpu_capabilities arm64_features[] = { 
		.cpu_enable = cpu_enable_dit,

		ARM64_CPUID_FIELDS(ID_AA64PFR0_EL1, DIT, IMP)

	},

	{

		.desc = "VHE for hypervisor only",

		.capability = ARM64_KVM_HVHE,

		.type = ARM64_CPUCAP_SYSTEM_FEATURE,

		.matches = hvhe_possible,

	},

	{},

};

arch/arm64/tools/cpucaps

+1 −0
Original line number Diff line number Diff line
@@ -47,6 +47,7 @@ HAS_TLB_RANGE 
HAS_VIRT_HOST_EXTN

HAS_WFXT

HW_DBM

KVM_HVHE

KVM_PROTECTED_MODE

MISMATCHED_CACHE_TYPE

MTE