Commit 4c360db6 authored by Jan Beulich's avatar Jan Beulich Committed by Boris Ostrovsky
Browse files

xen/x86: adjust xen_set_fixmap() 



Using __native_set_fixmap() here means guaranteed trap-and-emulate
instances the hypervisor has to deal with. Since the virtual address
covered by the to be adjusted page table entry is easy to determine (and
actually already gets obtained in a special case), simply use an
available, easy to invoke hypercall instead.

Signed-off-by: default avatarJan Beulich <jbeulich@suse.com>
Reviewed-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/11fcaea2-ec17-3edd-ecdf-4cdd2d472bd0@suse.com


Signed-off-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
parent cae73951

arch/x86/xen/mmu_pv.c

+5 −4
Original line number Diff line number Diff line
@@ -2011,6 +2011,7 @@ static unsigned char dummy_mapping[PAGE_SIZE] __page_aligned_bss; 
static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)

{

	pte_t pte;

	unsigned long vaddr;



	phys >>= PAGE_SHIFT;
@@ -2051,15 +2052,15 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot) 
		break;

	}



	__native_set_fixmap(idx, pte);

	vaddr = __fix_to_virt(idx);

	if (HYPERVISOR_update_va_mapping(vaddr, pte, UVMF_INVLPG))

		BUG();



#ifdef CONFIG_X86_VSYSCALL_EMULATION

	/* Replicate changes to map the vsyscall page into the user

	   pagetable vsyscall mapping. */

	if (idx == VSYSCALL_PAGE) {

		unsigned long vaddr = __fix_to_virt(idx);

	if (idx == VSYSCALL_PAGE)

		set_pte_vaddr_pud(level3_user_vsyscall, vaddr, pte);

	}

#endif

}