Commit 3bb7dceb authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

Merge tag 'kvmarm-fixes-6.14-2' of... 

Merge tag 'kvmarm-fixes-6.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.14, take #2

- Large set of fixes for vector handling, specially in the interactions
  between host and guest state. This fixes a number of bugs affecting
  actual deployments, and greatly simplifies the FP/SIMD/SVE handling.
  Thanks to Mark Rutland for dealing with this thankless task.

- Fix an ugly race between vcpu and vgic creation/init, resulting in
  unexpected behaviours.

- Fix use of kernel VAs at EL2 when emulating timers with nVHE.

- Small set of pKVM improvements and cleanups.
parents 43fb96ae b3aa9283

arch/arm64/include/asm/kvm_emulate.h

+0 −42
Original line number Diff line number Diff line
@@ -605,48 +605,6 @@ static __always_inline void kvm_incr_pc(struct kvm_vcpu *vcpu) 
					 __cpacr_to_cptr_set(clr, set));\

	} while (0)



static __always_inline void kvm_write_cptr_el2(u64 val)

{

	if (has_vhe() || has_hvhe())

		write_sysreg(val, cpacr_el1);

	else

		write_sysreg(val, cptr_el2);

}



/* Resets the value of cptr_el2 when returning to the host. */

static __always_inline void __kvm_reset_cptr_el2(struct kvm *kvm)

{

	u64 val;



	if (has_vhe()) {

		val = (CPACR_EL1_FPEN | CPACR_EL1_ZEN_EL1EN);

		if (cpus_have_final_cap(ARM64_SME))

			val |= CPACR_EL1_SMEN_EL1EN;

	} else if (has_hvhe()) {

		val = CPACR_EL1_FPEN;



		if (!kvm_has_sve(kvm) || !guest_owns_fp_regs())

			val |= CPACR_EL1_ZEN;

		if (cpus_have_final_cap(ARM64_SME))

			val |= CPACR_EL1_SMEN;

	} else {

		val = CPTR_NVHE_EL2_RES1;



		if (kvm_has_sve(kvm) && guest_owns_fp_regs())

			val |= CPTR_EL2_TZ;

		if (!cpus_have_final_cap(ARM64_SME))

			val |= CPTR_EL2_TSM;

	}



	kvm_write_cptr_el2(val);

}



#ifdef __KVM_NVHE_HYPERVISOR__

#define kvm_reset_cptr_el2(v)	__kvm_reset_cptr_el2(kern_hyp_va((v)->kvm))

#else

#define kvm_reset_cptr_el2(v)	__kvm_reset_cptr_el2((v)->kvm)

#endif



/*

 * Returns a 'sanitised' view of CPTR_EL2, translating from nVHE to the VHE

 * format if E2H isn't set.

arch/arm64/include/asm/kvm_host.h

+6 −18
Original line number Diff line number Diff line
@@ -100,7 +100,7 @@ static inline void push_hyp_memcache(struct kvm_hyp_memcache *mc, 
static inline void *pop_hyp_memcache(struct kvm_hyp_memcache *mc,

				     void *(*to_va)(phys_addr_t phys))

{

	phys_addr_t *p = to_va(mc->head);

	phys_addr_t *p = to_va(mc->head & PAGE_MASK);



	if (!mc->nr_pages)

		return NULL;
@@ -615,8 +615,6 @@ struct cpu_sve_state { 
struct kvm_host_data {

#define KVM_HOST_DATA_FLAG_HAS_SPE			0

#define KVM_HOST_DATA_FLAG_HAS_TRBE			1

#define KVM_HOST_DATA_FLAG_HOST_SVE_ENABLED		2

#define KVM_HOST_DATA_FLAG_HOST_SME_ENABLED		3

#define KVM_HOST_DATA_FLAG_TRBE_ENABLED			4

#define KVM_HOST_DATA_FLAG_EL1_TRACING_CONFIGURED	5

	unsigned long flags;
@@ -624,23 +622,13 @@ struct kvm_host_data { 
	struct kvm_cpu_context host_ctxt;



	/*

	 * All pointers in this union are hyp VA.

	 * Hyp VA.

	 * sve_state is only used in pKVM and if system_supports_sve().

	 */

	union {

		struct user_fpsimd_state *fpsimd_state;

	struct cpu_sve_state *sve_state;

	};



	union {

		/* HYP VA pointer to the host storage for FPMR */

		u64	*fpmr_ptr;

		/*

		 * Used by pKVM only, as it needs to provide storage

		 * for the host

		 */

	/* Used by pKVM only. */

	u64	fpmr;

	};



	/* Ownership of the FP regs */

	enum {

arch/arm64/kernel/fpsimd.c

+0 −25
Original line number Diff line number Diff line
@@ -1694,31 +1694,6 @@ void fpsimd_signal_preserve_current_state(void) 
		sve_to_fpsimd(current);

}



/*

 * Called by KVM when entering the guest.

 */

void fpsimd_kvm_prepare(void)

{

	if (!system_supports_sve())

		return;



	/*

	 * KVM does not save host SVE state since we can only enter

	 * the guest from a syscall so the ABI means that only the

	 * non-saved SVE state needs to be saved.  If we have left

	 * SVE enabled for performance reasons then update the task

	 * state to be FPSIMD only.

	 */

	get_cpu_fpsimd_context();



	if (test_and_clear_thread_flag(TIF_SVE)) {

		sve_to_fpsimd(current);

		current->thread.fp_type = FP_STATE_FPSIMD;

	}



	put_cpu_fpsimd_context();

}



/*

 * Associate current's FPSIMD context with this cpu

 * The caller must have ownership of the cpu FPSIMD context before calling

arch/arm64/kvm/arch_timer.c

+7 −9
Original line number Diff line number Diff line
@@ -447,21 +447,19 @@ static void kvm_timer_update_status(struct arch_timer_context *ctx, bool level) 
static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level,

				 struct arch_timer_context *timer_ctx)

{

	int ret;



	kvm_timer_update_status(timer_ctx, new_level);



	timer_ctx->irq.level = new_level;

	trace_kvm_timer_update_irq(vcpu->vcpu_id, timer_irq(timer_ctx),

				   timer_ctx->irq.level);



	if (!userspace_irqchip(vcpu->kvm)) {

		ret = kvm_vgic_inject_irq(vcpu->kvm, vcpu,

	if (userspace_irqchip(vcpu->kvm))

		return;



	kvm_vgic_inject_irq(vcpu->kvm, vcpu,

			    timer_irq(timer_ctx),

			    timer_ctx->irq.level,

			    timer_ctx);

		WARN_ON(ret);

	}

}



/* Only called for a fully emulated timer */

arch/arm64/kvm/arm.c

+0 −8
Original line number Diff line number Diff line
@@ -2481,14 +2481,6 @@ static void finalize_init_hyp_mode(void) 
			per_cpu_ptr_nvhe_sym(kvm_host_data, cpu)->sve_state =

				kern_hyp_va(sve_state);

		}

	} else {

		for_each_possible_cpu(cpu) {

			struct user_fpsimd_state *fpsimd_state;



			fpsimd_state = &per_cpu_ptr_nvhe_sym(kvm_host_data, cpu)->host_ctxt.fp_regs;

			per_cpu_ptr_nvhe_sym(kvm_host_data, cpu)->fpsimd_state =

				kern_hyp_va(fpsimd_state);

		}

	}

}