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authorKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2012-10-10 13:25:48 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-10-21 09:27:58 -0700
commitc525d8ee0c7701d72d8144f536d47a5bd30159e9 (patch)
treec80611156fbfc37ce354207dba24088c6eb08e86 /arch
parente1621ec4754097582c73c0ed8c394dcc50b1e0fd (diff)
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.c16
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,