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| author |   Linus Torvalds <torvalds@linux-foundation.org> | 2018-05-11 12:30:34 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-05-11 12:30:34 -0700 |
| commit | 84c3a0979c4c29711807747280dfecbb54b8af7c (patch) | |
| tree | 1df3ac089378c58fa97e24532680c7795e8ba379 | |
| parent | mmap: introduce sane default mmap limits (diff) | |
| parent | x86/xen: Reset VCPU0 info pointer after shared_info remap (diff) | |
| download | wireguard-linux-84c3a0979c4c29711807747280dfecbb54b8af7c.tar.xz wireguard-linux-84c3a0979c4c29711807747280dfecbb54b8af7c.zip | |
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
| -rw-r--r-- | arch/x86/xen/enlighten_hvm.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c index 826898701045..19c1ff542387 100644 --- a/arch/x86/xen/enlighten_hvm.c +++ b/arch/x86/xen/enlighten_hvm.c @@ -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) |