[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH 05/16] x86: map/unmap pages in restore_all_guests.
From: Hongyan Xia <hongyxia@xxxxxxxxxx> Before, it assumed the pv cr3 could be accessed via a direct map. This is no longer true. Note that we do not map and unmap root_pgt for now since it is still a xenheap page. Signed-off-by: Hongyan Xia <hongyxia@xxxxxxxxxx> --- xen/arch/x86/x86_64/entry.S | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) diff --git a/xen/arch/x86/x86_64/entry.S b/xen/arch/x86/x86_64/entry.S index d55453f3f3..110cd0394f 100644 --- a/xen/arch/x86/x86_64/entry.S +++ b/xen/arch/x86/x86_64/entry.S @@ -154,7 +154,24 @@ restore_all_guest: and %rsi, %rdi and %r9, %rsi add %rcx, %rdi - add %rcx, %rsi + + /* + * Without a direct map, we have to map first before copying. We only + * need to map the guest root table but not the per-CPU root_pgt, + * because the latter is still a xenheap page. + */ + pushq %r9 + pushq %rdx + pushq %rax + pushq %rdi + mov %rsi, %rdi + shr $PAGE_SHIFT, %rdi + callq map_domain_page + mov %rax, %rsi + popq %rdi + /* Stash the pointer for unmapping later. */ + pushq %rax + mov $ROOT_PAGETABLE_FIRST_XEN_SLOT, %ecx mov root_table_offset(SH_LINEAR_PT_VIRT_START)*8(%rsi), %r8 mov %r8, root_table_offset(SH_LINEAR_PT_VIRT_START)*8(%rdi) @@ -166,6 +183,14 @@ restore_all_guest: sub $(ROOT_PAGETABLE_FIRST_XEN_SLOT - \ ROOT_PAGETABLE_LAST_XEN_SLOT - 1) * 8, %rdi rep movsq + + /* Unmap the page. */ + popq %rdi + callq unmap_domain_page + popq %rax + popq %rdx + popq %r9 + .Lrag_copy_done: mov %r9, STACK_CPUINFO_FIELD(xen_cr3)(%rdx) movb $1, STACK_CPUINFO_FIELD(use_pv_cr3)(%rdx) -- 2.24.1.AMZN
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