xen: fix for 4.17-rc5

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Merge tag 'for-linus-4.17-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen fix from Juergen Gross:
 "One fix for the kernel running as a fully virtualized guest using PV
  drivers on old Xen hypervisor versions"

* tag 'for-linus-4.17-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/xen: Reset VCPU0 info pointer after shared_info remap
This commit is contained in:
Linus Torvalds 2018-05-11 12:30:34 -07:00
commit 84c3a0979c

View File

@ -65,6 +65,19 @@ static void __init xen_hvm_init_mem_mapping(void)
{
early_memunmap(HYPERVISOR_shared_info, PAGE_SIZE);
HYPERVISOR_shared_info = __va(PFN_PHYS(shared_info_pfn));
/*
* The virtual address of the shared_info page has changed, so
* the vcpu_info pointer for VCPU 0 is now stale.
*
* The prepare_boot_cpu callback will re-initialize it via
* xen_vcpu_setup, but we can't rely on that to be called for
* old Xen versions (xen_have_vector_callback == 0).
*
* It is, in any case, bad to have a stale vcpu_info pointer
* so reset it now.
*/
xen_vcpu_info_reset(0);
}
static void __init init_hvm_pv_info(void)