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Commit 98732d1b authored by Kristina Martsenko's avatar Kristina Martsenko Committed by Catalin Marinas
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KVM: arm/arm64: fix HYP ID map extension to 52 bits 



Commit fa2a8445 incorrectly masks the index of the HYP ID map pgd
entry, causing a non-VHE kernel to hang during boot. This happens when
VA_BITS=48 and the ID map text is in 52-bit physical memory. In this
case we don't need an extra table level but need more entries in the
top-level table, so we need to map into hyp_pgd and need to use
__kvm_idmap_ptrs_per_pgd to mask in the extra bits. However,
__create_hyp_mappings currently masks by PTRS_PER_PGD instead.

Fix it so that we always use __kvm_idmap_ptrs_per_pgd for the HYP ID
map. This ensures that we use the larger mask for the top-level ID map
table when it has more entries. In all other cases, PTRS_PER_PGD is used
as normal.

Fixes: fa2a8445 ("arm64: allow ID map to be extended to 52 bits")
Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarKristina Martsenko <kristina.martsenko@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 6a205420

virt/kvm/arm/mmu.c

+6 −12
Original line number Diff line number Diff line
@@ -623,21 +623,15 @@ static int create_hyp_pud_mappings(pgd_t *pgd, unsigned long start, 
	return 0;

}



static int __create_hyp_mappings(pgd_t *pgdp,

static int __create_hyp_mappings(pgd_t *pgdp, unsigned long ptrs_per_pgd,

				 unsigned long start, unsigned long end,

				 unsigned long pfn, pgprot_t prot)

{

	pgd_t *pgd;

	pud_t *pud;

	unsigned long addr, next, ptrs_per_pgd = PTRS_PER_PGD;

	unsigned long addr, next;

	int err = 0;



	/*

	 * If it's not the hyp_pgd, fall back to the kvm idmap layout.

	 */

	if (pgdp != hyp_pgd)

		ptrs_per_pgd = __kvm_idmap_ptrs_per_pgd();



	mutex_lock(&kvm_hyp_pgd_mutex);

	addr = start & PAGE_MASK;

	end = PAGE_ALIGN(end);
@@ -705,8 +699,8 @@ int create_hyp_mappings(void *from, void *to, pgprot_t prot) 
		int err;



		phys_addr = kvm_kaddr_to_phys(from + virt_addr - start);

		err = __create_hyp_mappings(hyp_pgd, virt_addr,

					    virt_addr + PAGE_SIZE,

		err = __create_hyp_mappings(hyp_pgd, PTRS_PER_PGD,

					    virt_addr, virt_addr + PAGE_SIZE,

					    __phys_to_pfn(phys_addr),

					    prot);

		if (err)
@@ -737,7 +731,7 @@ int create_hyp_io_mappings(void *from, void *to, phys_addr_t phys_addr) 
	if (!is_vmalloc_addr(from) || !is_vmalloc_addr(to - 1))

		return -EINVAL;



	return __create_hyp_mappings(hyp_pgd, start, end,

	return __create_hyp_mappings(hyp_pgd, PTRS_PER_PGD, start, end,

				     __phys_to_pfn(phys_addr), PAGE_HYP_DEVICE);

}
@@ -1743,7 +1737,7 @@ static int kvm_map_idmap_text(pgd_t *pgd) 
	int err;



	/* Create the idmap in the boot page tables */

	err = 	__create_hyp_mappings(pgd,

	err = 	__create_hyp_mappings(pgd, __kvm_idmap_ptrs_per_pgd(),

				      hyp_idmap_start, hyp_idmap_end,

				      __phys_to_pfn(hyp_idmap_start),

				      PAGE_HYP_EXEC);