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Commit 68240e9b authored by Marc Zyngier's avatar Marc Zyngier Committed by Greg Kroah-Hartman
Browse files

arm64: KVM: Add ARCH_WORKAROUND_2 support for guests 



commit 55e3748e8902ff641e334226bdcb432f9a5d78d3 upstream.

In order to offer ARCH_WORKAROUND_2 support to guests, we need
a bit of infrastructure.

Let's add a flag indicating whether or not the guest uses
SSBD mitigation. Depending on the state of this flag, allow
KVM to disable ARCH_WORKAROUND_2 before entering the guest,
and enable it when exiting it.

Reviewed-by: default avatarChristoffer Dall <christoffer.dall@arm.com>
Reviewed-by: default avatarMark Rutland <mark.rutland@arm.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7b62e850

arch/arm/include/asm/kvm_mmu.h

+5 −0
Original line number Diff line number Diff line
@@ -256,6 +256,11 @@ static inline int kvm_map_vectors(void) 
	return 0;

}



static inline int hyp_map_aux_data(void)

{

	return 0;

}



#endif	/* !__ASSEMBLY__ */



#endif /* __ARM_KVM_MMU_H__ */

arch/arm/kvm/arm.c

+6 −0
Original line number Diff line number Diff line
@@ -1367,6 +1367,12 @@ static int init_hyp_mode(void) 
		}

	}



	err = hyp_map_aux_data();

	if (err) {

		kvm_err("Cannot map host auxilary data: %d\n", err);

		goto out_err;

	}



	kvm_info("Hyp mode initialized successfully\n");



	return 0;

arch/arm64/include/asm/kvm_asm.h

+3 −0
Original line number Diff line number Diff line
@@ -33,6 +33,9 @@ 
#define KVM_ARM64_DEBUG_DIRTY_SHIFT	0

#define KVM_ARM64_DEBUG_DIRTY		(1 << KVM_ARM64_DEBUG_DIRTY_SHIFT)



#define	VCPU_WORKAROUND_2_FLAG_SHIFT	0

#define	VCPU_WORKAROUND_2_FLAG		(_AC(1, UL) << VCPU_WORKAROUND_2_FLAG_SHIFT)



/* Translate a kernel address of @sym into its equivalent linear mapping */

#define kvm_ksym_ref(sym)						\

	({								\

arch/arm64/include/asm/kvm_host.h

+3 −0
Original line number Diff line number Diff line
@@ -213,6 +213,9 @@ struct kvm_vcpu_arch { 
	/* Exception Information */

	struct kvm_vcpu_fault_info fault;



	/* State of various workarounds, see kvm_asm.h for bit assignment */

	u64 workaround_flags;



	/* Guest debug state */

	u64 debug_flags;

arch/arm64/include/asm/kvm_mmu.h

+24 −0
Original line number Diff line number Diff line
@@ -387,5 +387,29 @@ static inline int kvm_map_vectors(void) 
}

#endif



#ifdef CONFIG_ARM64_SSBD

DECLARE_PER_CPU_READ_MOSTLY(u64, arm64_ssbd_callback_required);



static inline int hyp_map_aux_data(void)

{

	int cpu, err;



	for_each_possible_cpu(cpu) {

		u64 *ptr;



		ptr = per_cpu_ptr(&arm64_ssbd_callback_required, cpu);

		err = create_hyp_mappings(ptr, ptr + 1, PAGE_HYP);

		if (err)

			return err;

	}

	return 0;

}

#else

static inline int hyp_map_aux_data(void)

{

	return 0;

}

#endif



#endif /* __ASSEMBLY__ */

#endif /* __ARM64_KVM_MMU_H__ */