Add the needed code to setup the hypercall page for calling into the
Xen hypervisor.
Signed-off-by: Juergen Gross <jgr...@suse.com>
---
V3: grub_xen_early_halt->grub_xen_panic (Roger Pau Monné)
issue panic message (Roger Pau Monné)
rewrite grub_xen_hypercall to avoid register variables (Daniel Kiper)
---
grub-core/kern/i386/xen/pvh.c | 69 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 69 insertions(+)
diff --git a/grub-core/kern/i386/xen/pvh.c b/grub-core/kern/i386/xen/pvh.c
index ac6181f4e..7e90a4538 100644
--- a/grub-core/kern/i386/xen/pvh.c
+++ b/grub-core/kern/i386/xen/pvh.c
@@ -20,14 +20,83 @@
#include <grub/misc.h>
#include <grub/memory.h>
#include <grub/mm.h>
+#include <grub/i386/cpuid.h>
+#include <grub/i386/io.h>
#include <grub/xen.h>
#include <grub/machine/kernel.h>
+#define XEN_CONSOLE_PORT 0xe9
+
grub_uint64_t grub_rsdp_addr;
+static char hypercall_page[GRUB_XEN_PAGE_SIZE]
+ __attribute__ ((aligned (GRUB_XEN_PAGE_SIZE)));
+
+static grub_uint32_t xen_cpuid_base;
+
+static void
+grub_xen_panic (const char *msg)
+{
+ const char *c;
+
+ for (c = msg; *c; c++)
+ grub_outb (*c, XEN_CONSOLE_PORT);
+
+ asm volatile ("hlt");
+}
+
+static void
+grub_xen_cpuid_base (void)
+{
+ grub_uint32_t base, eax, signature[3];
+
+ for (base = 0x40000000; base < 0x40010000; base += 0x100)
+ {
+ grub_cpuid (base, eax, signature[0], signature[1], signature[2]);
+ if (!grub_memcmp ("XenVMMXenVMM", signature, 12) && (eax - base) >= 2)
+ {
+ xen_cpuid_base = base;
+ return;
+ }
+ }
+
+ grub_xen_panic ("Found no Xen signature.\n");
+}
+
+static void
+grub_xen_setup_hypercall_page (void)
+{
+ grub_uint32_t msr, pfn, eax, ebx, ecx, edx;
+
+ grub_cpuid (xen_cpuid_base + 2, eax, ebx, ecx, edx);
+ msr = ebx;
+ pfn = (grub_uint32_t) (&hypercall_page[0]);
+
+ asm volatile ("wrmsr" : : "c" (msr), "a" (pfn), "d" (0) : "memory");
+}
+
+int
+grub_xen_hypercall (grub_uint32_t callno, grub_uint32_t a0,
+ grub_uint32_t a1, grub_uint32_t a2,
+ grub_uint32_t a3, grub_uint32_t a4,
+ grub_uint32_t a5 __attribute__ ((unused)))
+{
+ grub_uint32_t __res, __ign0, __ign1, __ign2, __ign3, __ign4;
+
+ asm volatile ("call *%[callno]"
+ : "=a" (__res), "=b" (__ign0), "=c" (__ign1), "=d" (__ign2),
+ "=S" (__ign3), "=D" (__ign4)
+ : "1" (a0), "2" (a1), "3" (a2), "4" (a3), "5" (a4),
+ [callno] "a" (&hypercall_page[callno * 32])
+ : "memory");
+ return __res;
+}
+
void
grub_xen_setup_pvh (void)
{
+ grub_xen_cpuid_base ();
+ grub_xen_setup_hypercall_page ();
}
grub_err_t
--
2.16.4
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