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| author | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2012-10-10 13:25:48 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-21 09:27:58 -0700 |
| commit | c525d8ee0c7701d72d8144f536d47a5bd30159e9 (patch) | |
| tree | c80611156fbfc37ce354207dba24088c6eb08e86 /arch | |
| parent | e1621ec4754097582c73c0ed8c394dcc50b1e0fd (diff) | |
| download | lwn-c525d8ee0c7701d72d8144f536d47a5bd30159e9.tar.gz lwn-c525d8ee0c7701d72d8144f536d47a5bd30159e9.zip | |
xen/bootup: allow {read|write}_cr8 pvops call.
commit 1a7bbda5b1ab0e02622761305a32dc38735b90b2 upstream.
We actually do not do anything about it. Just return a default
value of zero and if the kernel tries to write anything but 0
we BUG_ON.
This fixes the case when an user tries to suspend the machine
and it blows up in save_processor_state b/c 'read_cr8' is set
to NULL and we get:
kernel BUG at /home/konrad/ssd/linux/arch/x86/include/asm/paravirt.h:100!
invalid opcode: 0000 [#1] SMP
Pid: 2687, comm: init.late Tainted: G O 3.6.0upstream-00002-gac264ac-dirty #4 Bochs Bochs
RIP: e030:[<ffffffff814d5f42>] [<ffffffff814d5f42>] save_processor_state+0x212/0x270
.. snip..
Call Trace:
[<ffffffff810733bf>] do_suspend_lowlevel+0xf/0xac
[<ffffffff8107330c>] ? x86_acpi_suspend_lowlevel+0x10c/0x150
[<ffffffff81342ee2>] acpi_suspend_enter+0x57/0xd5
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/xen/enlighten.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 40edfc37a6fd..5fa38a80000c 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -942,7 +942,16 @@ static void xen_write_cr4(unsigned long cr4) native_write_cr4(cr4); } - +#ifdef CONFIG_X86_64 +static inline unsigned long xen_read_cr8(void) +{ + return 0; +} +static inline void xen_write_cr8(unsigned long val) +{ + BUG_ON(val); +} +#endif static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high) { int ret; @@ -1111,6 +1120,11 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst = { .read_cr4_safe = native_read_cr4_safe, .write_cr4 = xen_write_cr4, +#ifdef CONFIG_X86_64 + .read_cr8 = xen_read_cr8, + .write_cr8 = xen_write_cr8, +#endif + .wbinvd = native_wbinvd, .read_msr = native_read_msr_safe, |