plain text document attachment (xx-paravirt-vsyscall.patch)
vsyscall interface updates for paravirt ops.
Signed-off-by: Steven Rostedt srostedt@xxxxxxxxxx
Signed-off-by: Glauber de Oliveira Costa <gcosta@xxxxxxxxxx>
Index: clean-start/arch/x86_64/kernel/vsyscall.c
===================================================================
--- clean-start.orig/arch/x86_64/kernel/vsyscall.c
+++ clean-start/arch/x86_64/kernel/vsyscall.c
@@ -73,7 +73,7 @@ static __always_inline void do_vgettimeo
usec = __xtime.tv_nsec / 1000;
if (__vxtime.mode != VXTIME_HPET) {
- t = get_cycles_sync();
+ t = vget_cycles_sync();
if (t < __vxtime.last_tsc)
t = __vxtime.last_tsc;
usec += ((t - __vxtime.last_tsc) *
@@ -147,8 +147,8 @@ time_t __vsyscall(1) vtime(time_t *t)
long __vsyscall(2)
vgetcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *tcache)
{
- unsigned int dummy, p;
- unsigned long j = 0;
+ unsigned int p;
+ unsigned long dummy, j = 0;
/* Fast cache - only recompute value once per jiffies and avoid
relatively costly rdtscp/cpuid otherwise.
@@ -162,7 +162,8 @@ vgetcpu(unsigned *cpu, unsigned *node, s
p = tcache->blob[1];
} else if (__vgetcpu_mode == VGETCPU_RDTSCP) {
/* Load per CPU data from RDTSCP */
- rdtscp(dummy, dummy, p);
+ /* rdtscp() cannot be called due to the paravirt indirection */
+ asm("rdtscp" : "=A" (dummy), "=c" (p));
} else {
/* Load per CPU data from GDT */
asm("lsl %1,%0" : "=r" (p) : "r" (__PER_CPU_SEG));
@@ -256,7 +257,11 @@ static void __cpuinit vsyscall_set_cpu(i
node = cpu_to_node[cpu];
#endif
if (cpu_has(&cpu_data[cpu], X86_FEATURE_RDTSCP))
- write_rdtscp_aux((node << 12) | cpu);
+ /* This is write_rdtscp_aux. It cannot be called directly
+ * due to the paravirt indirection */
+ asm("wrmsr" : /* no output */
+ : "d"(0),
+ "a" ((node << 12) | cpu), "c" (0xc0000103));
/* Store cpu number in limit so that it can be loaded quickly
in user space in vgetcpu.
@@ -285,8 +290,12 @@ cpu_vsyscall_notifier(struct notifier_bl
static void __init map_vsyscall(void)
{
+#ifndef CONFIG_PARAVIRT
extern char __vsyscall_0;
unsigned long physaddr_page0 = __pa_symbol(&__vsyscall_0);
+#else
+ unsigned long physaddr_page0 = __pa_symbol(paravirt_ops.vsyscall_page);
+#endif
/* Note that VSYSCALL_MAPPED_PAGES must agree with the code below. */
__set_fixmap(VSYSCALL_FIRST_PAGE, physaddr_page0, PAGE_KERNEL_VSYSCALL);
@@ -299,7 +308,14 @@ static int __init vsyscall_init(void)
BUG_ON((unsigned long) &vtime != VSYSCALL_ADDR(__NR_vtime));
BUG_ON((VSYSCALL_ADDR(0) != __fix_to_virt(VSYSCALL_FIRST_PAGE)));
BUG_ON((unsigned long) &vgetcpu != VSYSCALL_ADDR(__NR_vgetcpu));
- map_vsyscall();
+#ifdef CONFIG_PARAVIRT
+ if (paravirt_ops.vsyscall_page)
+#endif
+ map_vsyscall();
+#ifdef CONFIG_PARAVIRT
+ else
+ __sysctl_vsyscall = 0;
+#endif
#ifdef CONFIG_SYSCTL
register_sysctl_table(kernel_root_table2, 0);
#endif
--
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