[PATCH v2 06/22] mini-os: setup hypercall page for HVMlite

[Juergen Gross <jgross@suse.com>]

When running in HVMlite mode we need to setup the hypercall page by
ourself.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
---
V2: move wrmsr definitions as requested by Samuel Thibault
---
 arch/x86/events.c |  4 ++--
 arch/x86/setup.c  | 26 ++++++++++++++++++++++++++
 include/x86/os.h  | 28 ++++++++++++++++++++--------
 3 files changed, 48 insertions(+), 10 deletions(-)

diff --git a/arch/x86/events.c b/arch/x86/events.c
index 5198cf3..342662d 100644
--- a/arch/x86/events.c
+++ b/arch/x86/events.c
@@ -16,7 +16,7 @@ void arch_init_events(void)
 {
 #if defined(__x86_64__)
     asm volatile("movl %0,%%fs ; movl %0,%%gs" :: "r" (0));
-    wrmsrl(0xc0000101, &cpu0_pda); /* 0xc0000101 is MSR_GS_BASE */
+    wrmsrl(0xc0000101, (uint64_t)&cpu0_pda); /* 0xc0000101 is MSR_GS_BASE */
     cpu0_pda.irqcount = -1;
     cpu0_pda.irqstackptr = (void*) (((unsigned long)irqstack + 2 * STACK_SIZE)
                                     & ~(STACK_SIZE - 1));
@@ -30,6 +30,6 @@ void arch_unbind_ports(void)
 void arch_fini_events(void)
 {
 #if defined(__x86_64__)
-    wrmsrl(0xc0000101, NULL); /* 0xc0000101 is MSR_GS_BASE */
+    wrmsrl(0xc0000101, 0); /* 0xc0000101 is MSR_GS_BASE */
 #endif
 }
diff --git a/arch/x86/setup.c b/arch/x86/setup.c
index 30a9143..edc4ca4 100644
--- a/arch/x86/setup.c
+++ b/arch/x86/setup.c
@@ -30,6 +30,7 @@
 #include <mini-os/lib.h> /* for printk, memcpy */
 #include <mini-os/kernel.h>
 #include <xen/xen.h>
+#include <xen/arch-x86/cpuid.h>
 
 /*
  * Shared page for communicating with the hypervisor.
@@ -89,6 +90,30 @@ static inline void sse_init(void) {
 #define sse_init()
 #endif
 
+#ifdef CONFIG_PARAVIRT
+#define hpc_init()
+#else
+static void hpc_init(void)
+{
+    uint32_t eax, ebx, ecx, edx, base;
+
+    for ( base = XEN_CPUID_FIRST_LEAF;
+          base < XEN_CPUID_FIRST_LEAF + 0x10000; base += 0x100 )
+    {
+        cpuid(base, &eax, &ebx, &ecx, &edx);
+
+        if ( (ebx == XEN_CPUID_SIGNATURE_EBX) &&
+             (ecx == XEN_CPUID_SIGNATURE_ECX) &&
+             (edx == XEN_CPUID_SIGNATURE_EDX) &&
+             ((eax - base) >= 2) )
+            break;
+    }
+
+    cpuid(base + 2, &eax, &ebx, &ecx, &edx);
+    wrmsrl(ebx, (unsigned long)&hypercall_page);
+    barrier();
+}
+#endif
 
 /*
  * INITIAL C ENTRY POINT.
@@ -99,6 +124,7 @@ arch_init(void *par)
 	static char hello[] = "Bootstrapping...\n";
 	start_info_t *si;
 
+	hpc_init();
 	(void)HYPERVISOR_console_io(CONSOLEIO_write, strlen(hello), hello);
 
 	trap_init();
diff --git a/include/x86/os.h b/include/x86/os.h
index eeefbe2..7b7869a 100644
--- a/include/x86/os.h
+++ b/include/x86/os.h
@@ -440,20 +440,23 @@ static __inline__ unsigned long __ffs(unsigned long word)
      (val) = ((unsigned long)__a) | (((unsigned long)__d)<<32); \
 } while(0)
 
-#define wrmsr(msr,val1,val2) \
-      __asm__ __volatile__("wrmsr" \
-                           : /* no outputs */ \
-                           : "c" (msr), "a" (val1), "d" (val2))
-
-#define wrmsrl(msr,val) wrmsr(msr,(uint32_t)((uint64_t)(val)),((uint64_t)(val))>>32)
-
-
 #else /* ifdef __x86_64__ */
 #error "Unsupported architecture"
 #endif
+
 #endif /* ifdef __INSIDE_MINIOS */
 
 /********************* common i386 and x86_64  ****************************/
+#define wrmsr(msr,val1,val2) \
+      __asm__ __volatile__("wrmsr" \
+                           : /* no outputs */ \
+                           : "c" (msr), "a" (val1), "d" (val2))
+
+static inline void wrmsrl(unsigned msr, uint64_t val)
+{
+    wrmsr(msr, (uint32_t)(val & 0xffffffffULL), (uint32_t)(val >> 32));
+}
+
 struct __synch_xchg_dummy { unsigned long a[100]; };
 #define __synch_xg(x) ((struct __synch_xchg_dummy *)(x))
 
@@ -571,6 +574,15 @@ HYPERVISOR_xsm_op(
     return _hypercall1(int, xsm_op, op);
 }
 
+static inline void cpuid(uint32_t leaf,
+                         uint32_t *eax, uint32_t *ebx,
+                         uint32_t *ecx, uint32_t *edx)
+{
+    asm volatile ("cpuid"
+                  : "=a" (*eax), "=b" (*ebx), "=c" (*ecx), "=d" (*edx)
+                  : "0" (leaf));
+}
+
 #undef ADDR
 
 #endif /* not assembly */
-- 
2.6.6


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