Commit df4c8214 authored by David Brazdil's avatar David Brazdil Committed by Marc Zyngier
Browse files

kvm: arm64: Duplicate arm64_ssbd_callback_required for nVHE hyp 



Hyp keeps track of which cores require SSBD callback by accessing a
kernel-proper global variable. Create an nVHE symbol of the same name
and copy the value from kernel proper to nVHE as KVM is being enabled
on a core.

Done in preparation for separating percpu memory owned by kernel
proper and nVHE.

Signed-off-by: default avatarDavid Brazdil <dbrazdil@google.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Acked-by: default avatarWill Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200922204910.7265-8-dbrazdil@google.com
parent 57249499

arch/arm64/include/asm/kvm_mmu.h

+13 −1
Original line number Diff line number Diff line
@@ -529,6 +529,7 @@ static inline int kvm_map_vectors(void) 


#ifdef CONFIG_ARM64_SSBD

DECLARE_PER_CPU_READ_MOSTLY(u64, arm64_ssbd_callback_required);

DECLARE_KVM_NVHE_PER_CPU(u64, arm64_ssbd_callback_required);



static inline int hyp_map_aux_data(void)

{
@@ -537,18 +538,29 @@ static inline int hyp_map_aux_data(void) 
	for_each_possible_cpu(cpu) {

		u64 *ptr;



		ptr = per_cpu_ptr(&arm64_ssbd_callback_required, cpu);

		ptr = per_cpu_ptr_nvhe_sym(arm64_ssbd_callback_required, cpu);

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

		if (err)

			return err;

	}

	return 0;

}



static inline void hyp_init_aux_data(void)

{

	u64 *ptr;



	/* Copy arm64_ssbd_callback_required value from kernel to hyp. */

	ptr = this_cpu_ptr_nvhe_sym(arm64_ssbd_callback_required);

	*ptr = __this_cpu_read(arm64_ssbd_callback_required);

}

#else

static inline int hyp_map_aux_data(void)

{

	return 0;

}



static inline void hyp_init_aux_data(void) {}

#endif



#define kvm_phys_to_vttbr(addr)		phys_to_ttbr(addr)

arch/arm64/kernel/image-vars.h

+0 −1
Original line number Diff line number Diff line
@@ -67,7 +67,6 @@ KVM_NVHE_ALIAS(kvm_patch_vector_branch); 
KVM_NVHE_ALIAS(kvm_update_va_mask);



/* Global kernel state accessed by nVHE hyp code. */

KVM_NVHE_ALIAS(arm64_ssbd_callback_required);

KVM_NVHE_ALIAS(kvm_host_data);

KVM_NVHE_ALIAS(kvm_vgic_global_state);

arch/arm64/kvm/arm.c

+3 −0
Original line number Diff line number Diff line
@@ -1295,6 +1295,9 @@ static void cpu_init_hyp_mode(void) 
	    arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE) {

		kvm_call_hyp_nvhe(__kvm_enable_ssbs);

	}



	/* Copy information whether SSBD callback is required to hyp. */

	hyp_init_aux_data();

}



static void cpu_hyp_reset(void)

arch/arm64/kvm/hyp/nvhe/switch.c

+3 −0
Original line number Diff line number Diff line
@@ -27,6 +27,9 @@ 
#include <asm/processor.h>

#include <asm/thread_info.h>



/* Non-VHE copy of the kernel symbol. */

DEFINE_PER_CPU_READ_MOSTLY(u64, arm64_ssbd_callback_required);



static void __activate_traps(struct kvm_vcpu *vcpu)

{

	u64 val;

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