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Commit fb65675f authored by James Morse's avatar James Morse Committed by Greg Kroah-Hartman
Browse files

KVM: arm64: Allow SMCCC_ARCH_WORKAROUND_3 to be discovered and migrated 



commit a5905d6af492ee6a4a2205f0d550b3f931b03d03 upstream.

KVM allows the guest to discover whether the ARCH_WORKAROUND SMCCC are
implemented, and to preserve that state during migration through its
firmware register interface.

Add the necessary boiler plate for SMCCC_ARCH_WORKAROUND_3.

Reviewed-by: default avatarRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
[ kvm code moved to virt/kvm/arm. ]
Signed-off-by: default avatarJames Morse <james.morse@arm.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 9013fd4b

arch/arm/include/asm/kvm_host.h

+7 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <asm/kvm_asm.h>

#include <asm/kvm_mmio.h>

#include <asm/fpstate.h>

#include <asm/spectre.h>

#include <kvm/arm_arch_timer.h>



#define __KVM_HAVE_ARCH_INTC_INITIALIZED
@@ -424,4 +425,10 @@ static inline bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu) 


#define kvm_arm_vcpu_loaded(vcpu)	(false)



static inline int kvm_arm_get_spectre_bhb_state(void)

{

	/* 32bit guests don't need firmware for this */

	return SPECTRE_VULNERABLE; /* aka SMCCC_RET_NOT_SUPPORTED */

}



#endif /* __ARM_KVM_HOST_H__ */

arch/arm/include/uapi/asm/kvm.h

+6 −0
Original line number Diff line number Diff line
@@ -227,6 +227,12 @@ struct kvm_vcpu_events { 
#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED	3

#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_ENABLED	(1U << 4)



#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3	KVM_REG_ARM_FW_REG(3)

	/* Higher values mean better protection. */

#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_AVAIL		0

#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_AVAIL		1

#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_REQUIRED	2



/* Device Control API: ARM VGIC */

#define KVM_DEV_ARM_VGIC_GRP_ADDR	0

#define KVM_DEV_ARM_VGIC_GRP_DIST_REGS	1

arch/arm64/include/asm/kvm_host.h

+5 −0
Original line number Diff line number Diff line
@@ -684,4 +684,9 @@ bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu); 


#define kvm_arm_vcpu_loaded(vcpu)	((vcpu)->arch.sysregs_loaded_on_cpu)



static inline enum mitigation_state kvm_arm_get_spectre_bhb_state(void)

{

	return arm64_get_spectre_bhb_state();

}



#endif /* __ARM64_KVM_HOST_H__ */

arch/arm64/include/uapi/asm/kvm.h

+5 −0
Original line number Diff line number Diff line
@@ -240,6 +240,11 @@ struct kvm_vcpu_events { 
#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED	3

#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_ENABLED     	(1U << 4)



#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3	KVM_REG_ARM_FW_REG(3)

#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_AVAIL		0

#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_AVAIL		1

#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_REQUIRED	2



/* SVE registers */

#define KVM_REG_ARM64_SVE		(0x15 << KVM_REG_ARM_COPROC_SHIFT)

virt/kvm/arm/psci.c

+31 −3
Original line number Diff line number Diff line
@@ -426,6 +426,18 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) 
				break;

			}

			break;

		case ARM_SMCCC_ARCH_WORKAROUND_3:

			switch (kvm_arm_get_spectre_bhb_state()) {

			case SPECTRE_VULNERABLE:

				break;

			case SPECTRE_MITIGATED:

				val = SMCCC_RET_SUCCESS;

				break;

			case SPECTRE_UNAFFECTED:

				val = SMCCC_ARCH_WORKAROUND_RET_UNAFFECTED;

				break;

			}

			break;

		}

		break;

	default:
@@ -438,7 +450,7 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) 


int kvm_arm_get_fw_num_regs(struct kvm_vcpu *vcpu)

{

	return 3;		/* PSCI version and two workaround registers */

	return 4;		/* PSCI version and three workaround registers */

}



int kvm_arm_copy_fw_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
@@ -452,6 +464,9 @@ int kvm_arm_copy_fw_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices) 
	if (put_user(KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2, uindices++))

		return -EFAULT;



	if (put_user(KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3, uindices++))

		return -EFAULT;



	return 0;

}
@@ -486,8 +501,19 @@ static int get_kernel_wa_level(u64 regid) 
			return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED;

		case KVM_SSBD_UNKNOWN:

		default:

			break;

		}

		return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_UNKNOWN;

	case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3:

		switch (kvm_arm_get_spectre_bhb_state()) {

		case SPECTRE_VULNERABLE:

			return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_AVAIL;

		case SPECTRE_MITIGATED:

			return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_AVAIL;

		case SPECTRE_UNAFFECTED:

			return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_REQUIRED;

		}

		return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_AVAIL;

        }



	return -EINVAL;
@@ -503,6 +529,7 @@ int kvm_arm_get_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) 
		val = kvm_psci_version(vcpu, vcpu->kvm);

		break;

	case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1:

	case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3:

		val = get_kernel_wa_level(reg->id) & KVM_REG_FEATURE_LEVEL_MASK;

		break;

	case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2:
@@ -555,6 +582,7 @@ int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) 
	}



	case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1:

	case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3:

		if (val & ~KVM_REG_FEATURE_LEVEL_MASK)

			return -EINVAL;