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xen: Setup hypercall page for PVH

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Add the needed code to setup the hypercall page for calling into the
Xen hypervisor.

Import the XEN_HVM_DEBUGCONS_IOPORT define from Xen unstable into
include/xen/arch-x86/xen.h

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Tested-by: Hans van Kranenburg <hans@knorrie.org>
This commit is contained in:
Juergen Gross 2018-12-07 13:11:39 +01:00 committed by Vincent Batts
parent 590dd77f55
commit d0c68baa5b
2 changed files with 87 additions and 0 deletions
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80
grub-core/kern/i386/xen/pvh.c
View file

@ -20,15 +20,95 @@
#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 <xen/hvm/start_info.h>
#include <grub/machine/kernel.h>
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_cons_msg (const char *msg)
{
const char *c;
for (c = msg; *c; c++)
grub_outb (*c, XEN_HVM_DEBUGCONS_IOPORT);
}
static void
grub_xen_panic (const char *msg)
{
grub_xen_cons_msg (msg);
grub_xen_cons_msg ("System halted!\n");
asm volatile ("cli");
while (1)
{
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, addr, eax, ebx, ecx, edx;
/* Get base address of Xen-specific MSRs. */
grub_cpuid (xen_cpuid_base + 2, eax, ebx, ecx, edx);
msr = ebx;
addr = (grub_uint32_t) (&hypercall_page);
/* Specify hypercall page address for Xen. */
asm volatile ("wrmsr" : : "c" (msr), "a" (addr), "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;
asm volatile ("call *%[callno]"
: "=a" (res), "+b" (a0), "+c" (a1), "+d" (a2),
"+S" (a3), "+D" (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

7
include/xen/arch-x86/xen.h
View file

@ -260,6 +260,13 @@ typedef struct arch_shared_info arch_shared_info_t;
#define XEN_CPUID XEN_EMULATE_PREFIX "cpuid"
#endif
/*
* Debug console IO port, also called "port E9 hack". Each character written
* to this IO port will be printed on the hypervisor console, subject to log
* level restrictions.
*/
#define XEN_HVM_DEBUGCONS_IOPORT 0xe9
#endif /* __XEN_PUBLIC_ARCH_X86_XEN_H__ */
/*