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Commit f710a12d authored by Marcelo Tosatti's avatar Marcelo Tosatti Committed by Marcelo Tosatti
Browse files

Merge tag 'kvm-arm-fixes-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm 

Fixes for KVM/ARM for 4.0-rc5.

Fixes page refcounting issues in our Stage-2 page table management code,
fixes a missing unlock in a gicv3 error path, and fixes a race that can
cause lost interrupts if signals are pending just prior to entering the
guest.
parents 670125bd ae705930

arch/arm/include/asm/kvm_mmu.h

+6 −7
Original line number Diff line number Diff line
@@ -149,29 +149,28 @@ static inline bool kvm_s2pmd_readonly(pmd_t *pmd) 
	(__boundary - 1 < (end) - 1)? __boundary: (end);		\

})



#define kvm_pgd_index(addr)			pgd_index(addr)



static inline bool kvm_page_empty(void *ptr)

{

	struct page *ptr_page = virt_to_page(ptr);

	return page_count(ptr_page) == 1;

}





#define kvm_pte_table_empty(kvm, ptep) kvm_page_empty(ptep)

#define kvm_pmd_table_empty(kvm, pmdp) kvm_page_empty(pmdp)

#define kvm_pud_table_empty(kvm, pudp) (0)



#define KVM_PREALLOC_LEVEL	0



static inline int kvm_prealloc_hwpgd(struct kvm *kvm, pgd_t *pgd)

static inline void *kvm_get_hwpgd(struct kvm *kvm)

{

	return 0;

	return kvm->arch.pgd;

}



static inline void kvm_free_hwpgd(struct kvm *kvm) { }



static inline void *kvm_get_hwpgd(struct kvm *kvm)

static inline unsigned int kvm_get_hwpgd_size(void)

{

	return kvm->arch.pgd;

	return PTRS_PER_S2_PGD * sizeof(pgd_t);

}



struct kvm;

arch/arm/kvm/mmu.c

+53 −22
Original line number Diff line number Diff line
@@ -290,7 +290,7 @@ static void unmap_range(struct kvm *kvm, pgd_t *pgdp, 
	phys_addr_t addr = start, end = start + size;

	phys_addr_t next;



	pgd = pgdp + pgd_index(addr);

	pgd = pgdp + kvm_pgd_index(addr);

	do {

		next = kvm_pgd_addr_end(addr, end);

		if (!pgd_none(*pgd))
@@ -355,7 +355,7 @@ static void stage2_flush_memslot(struct kvm *kvm, 
	phys_addr_t next;

	pgd_t *pgd;



	pgd = kvm->arch.pgd + pgd_index(addr);

	pgd = kvm->arch.pgd + kvm_pgd_index(addr);

	do {

		next = kvm_pgd_addr_end(addr, end);

		stage2_flush_puds(kvm, pgd, addr, next);
@@ -632,6 +632,20 @@ int create_hyp_io_mappings(void *from, void *to, phys_addr_t phys_addr) 
				     __phys_to_pfn(phys_addr), PAGE_HYP_DEVICE);

}



/* Free the HW pgd, one page at a time */

static void kvm_free_hwpgd(void *hwpgd)

{

	free_pages_exact(hwpgd, kvm_get_hwpgd_size());

}



/* Allocate the HW PGD, making sure that each page gets its own refcount */

static void *kvm_alloc_hwpgd(void)

{

	unsigned int size = kvm_get_hwpgd_size();



	return alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);

}



/**

 * kvm_alloc_stage2_pgd - allocate level-1 table for stage-2 translation.

 * @kvm:	The KVM struct pointer for the VM.
@@ -645,15 +659,31 @@ int create_hyp_io_mappings(void *from, void *to, phys_addr_t phys_addr) 
 */

int kvm_alloc_stage2_pgd(struct kvm *kvm)

{

	int ret;

	pgd_t *pgd;

	void *hwpgd;



	if (kvm->arch.pgd != NULL) {

		kvm_err("kvm_arch already initialized?\n");

		return -EINVAL;

	}



	hwpgd = kvm_alloc_hwpgd();

	if (!hwpgd)

		return -ENOMEM;



	/* When the kernel uses more levels of page tables than the

	 * guest, we allocate a fake PGD and pre-populate it to point

	 * to the next-level page table, which will be the real

	 * initial page table pointed to by the VTTBR.

	 *

	 * When KVM_PREALLOC_LEVEL==2, we allocate a single page for

	 * the PMD and the kernel will use folded pud.

	 * When KVM_PREALLOC_LEVEL==1, we allocate 2 consecutive PUD

	 * pages.

	 */

	if (KVM_PREALLOC_LEVEL > 0) {

		int i;



		/*

		 * Allocate fake pgd for the page table manipulation macros to

		 * work.  This is not used by the hardware and we have no
@@ -661,30 +691,32 @@ int kvm_alloc_stage2_pgd(struct kvm *kvm) 
		 */

		pgd = (pgd_t *)kmalloc(PTRS_PER_S2_PGD * sizeof(pgd_t),

				       GFP_KERNEL | __GFP_ZERO);



		if (!pgd) {

			kvm_free_hwpgd(hwpgd);

			return -ENOMEM;

		}



		/* Plug the HW PGD into the fake one. */

		for (i = 0; i < PTRS_PER_S2_PGD; i++) {

			if (KVM_PREALLOC_LEVEL == 1)

				pgd_populate(NULL, pgd + i,

					     (pud_t *)hwpgd + i * PTRS_PER_PUD);

			else if (KVM_PREALLOC_LEVEL == 2)

				pud_populate(NULL, pud_offset(pgd, 0) + i,

					     (pmd_t *)hwpgd + i * PTRS_PER_PMD);

		}

	} else {

		/*

		 * Allocate actual first-level Stage-2 page table used by the

		 * hardware for Stage-2 page table walks.

		 */

		pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, S2_PGD_ORDER);

		pgd = (pgd_t *)hwpgd;

	}



	if (!pgd)

		return -ENOMEM;



	ret = kvm_prealloc_hwpgd(kvm, pgd);

	if (ret)

		goto out_err;



	kvm_clean_pgd(pgd);

	kvm->arch.pgd = pgd;

	return 0;

out_err:

	if (KVM_PREALLOC_LEVEL > 0)

		kfree(pgd);

	else

		free_pages((unsigned long)pgd, S2_PGD_ORDER);

	return ret;

}



/**
@@ -785,11 +817,10 @@ void kvm_free_stage2_pgd(struct kvm *kvm) 
		return;



	unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE);

	kvm_free_hwpgd(kvm);

	kvm_free_hwpgd(kvm_get_hwpgd(kvm));

	if (KVM_PREALLOC_LEVEL > 0)

		kfree(kvm->arch.pgd);

	else

		free_pages((unsigned long)kvm->arch.pgd, S2_PGD_ORDER);



	kvm->arch.pgd = NULL;

}
@@ -799,7 +830,7 @@ static pud_t *stage2_get_pud(struct kvm *kvm, struct kvm_mmu_memory_cache *cache 
	pgd_t *pgd;

	pud_t *pud;



	pgd = kvm->arch.pgd + pgd_index(addr);

	pgd = kvm->arch.pgd + kvm_pgd_index(addr);

	if (WARN_ON(pgd_none(*pgd))) {

		if (!cache)

			return NULL;
@@ -1089,7 +1120,7 @@ static void stage2_wp_range(struct kvm *kvm, phys_addr_t addr, phys_addr_t end) 
	pgd_t *pgd;

	phys_addr_t next;



	pgd = kvm->arch.pgd + pgd_index(addr);

	pgd = kvm->arch.pgd + kvm_pgd_index(addr);

	do {

		/*

		 * Release kvm_mmu_lock periodically if the memory region is

arch/arm64/include/asm/kvm_arm.h

+3 −2
Original line number Diff line number Diff line
@@ -129,6 +129,9 @@ 
 * 40 bits wide (T0SZ = 24).  Systems with a PARange smaller than 40 bits are

 * not known to exist and will break with this configuration.

 *

 * VTCR_EL2.PS is extracted from ID_AA64MMFR0_EL1.PARange at boot time

 * (see hyp-init.S).

 *

 * Note that when using 4K pages, we concatenate two first level page tables

 * together.

 *
@@ -138,7 +141,6 @@ 
#ifdef CONFIG_ARM64_64K_PAGES

/*

 * Stage2 translation configuration:

 * 40bits output (PS = 2)

 * 40bits input  (T0SZ = 24)

 * 64kB pages (TG0 = 1)

 * 2 level page tables (SL = 1)
@@ -150,7 +152,6 @@ 
#else

/*

 * Stage2 translation configuration:

 * 40bits output (PS = 2)

 * 40bits input  (T0SZ = 24)

 * 4kB pages (TG0 = 0)

 * 3 level page tables (SL = 1)

arch/arm64/include/asm/kvm_mmu.h

+6 −42
Original line number Diff line number Diff line
@@ -158,6 +158,8 @@ static inline bool kvm_s2pmd_readonly(pmd_t *pmd) 
#define PTRS_PER_S2_PGD		(1 << PTRS_PER_S2_PGD_SHIFT)

#define S2_PGD_ORDER		get_order(PTRS_PER_S2_PGD * sizeof(pgd_t))



#define kvm_pgd_index(addr)	(((addr) >> PGDIR_SHIFT) & (PTRS_PER_S2_PGD - 1))



/*

 * If we are concatenating first level stage-2 page tables, we would have less

 * than or equal to 16 pointers in the fake PGD, because that's what the
@@ -171,43 +173,6 @@ static inline bool kvm_s2pmd_readonly(pmd_t *pmd) 
#define KVM_PREALLOC_LEVEL	(0)

#endif



/**

 * kvm_prealloc_hwpgd - allocate inital table for VTTBR

 * @kvm:	The KVM struct pointer for the VM.

 * @pgd:	The kernel pseudo pgd

 *

 * When the kernel uses more levels of page tables than the guest, we allocate

 * a fake PGD and pre-populate it to point to the next-level page table, which

 * will be the real initial page table pointed to by the VTTBR.

 *

 * When KVM_PREALLOC_LEVEL==2, we allocate a single page for the PMD and

 * the kernel will use folded pud.  When KVM_PREALLOC_LEVEL==1, we

 * allocate 2 consecutive PUD pages.

 */

static inline int kvm_prealloc_hwpgd(struct kvm *kvm, pgd_t *pgd)

{

	unsigned int i;

	unsigned long hwpgd;



	if (KVM_PREALLOC_LEVEL == 0)

		return 0;



	hwpgd = __get_free_pages(GFP_KERNEL | __GFP_ZERO, PTRS_PER_S2_PGD_SHIFT);

	if (!hwpgd)

		return -ENOMEM;



	for (i = 0; i < PTRS_PER_S2_PGD; i++) {

		if (KVM_PREALLOC_LEVEL == 1)

			pgd_populate(NULL, pgd + i,

				     (pud_t *)hwpgd + i * PTRS_PER_PUD);

		else if (KVM_PREALLOC_LEVEL == 2)

			pud_populate(NULL, pud_offset(pgd, 0) + i,

				     (pmd_t *)hwpgd + i * PTRS_PER_PMD);

	}



	return 0;

}



static inline void *kvm_get_hwpgd(struct kvm *kvm)

{

	pgd_t *pgd = kvm->arch.pgd;
@@ -224,12 +189,11 @@ static inline void *kvm_get_hwpgd(struct kvm *kvm) 
	return pmd_offset(pud, 0);

}



static inline void kvm_free_hwpgd(struct kvm *kvm)

static inline unsigned int kvm_get_hwpgd_size(void)

{

	if (KVM_PREALLOC_LEVEL > 0) {

		unsigned long hwpgd = (unsigned long)kvm_get_hwpgd(kvm);

		free_pages(hwpgd, PTRS_PER_S2_PGD_SHIFT);

	}

	if (KVM_PREALLOC_LEVEL > 0)

		return PTRS_PER_S2_PGD * PAGE_SIZE;

	return PTRS_PER_S2_PGD * sizeof(pgd_t);

}



static inline bool kvm_page_empty(void *ptr)

include/kvm/arm_vgic.h

+1 −0
Original line number Diff line number Diff line
@@ -114,6 +114,7 @@ struct vgic_ops { 
	void	(*sync_lr_elrsr)(struct kvm_vcpu *, int, struct vgic_lr);

	u64	(*get_elrsr)(const struct kvm_vcpu *vcpu);

	u64	(*get_eisr)(const struct kvm_vcpu *vcpu);

	void	(*clear_eisr)(struct kvm_vcpu *vcpu);

	u32	(*get_interrupt_status)(const struct kvm_vcpu *vcpu);

	void	(*enable_underflow)(struct kvm_vcpu *vcpu);

	void	(*disable_underflow)(struct kvm_vcpu *vcpu);