# HG changeset patch
# User Keir Fraser <keir@xxxxxxxxxxxxx>
# Date 1191247925 -3600
# Node ID 772674585a1a367095fe326b8a659f674099a241
# Parent 9eff4c97053b866a1803ce1a85a231e2821ea598
hvm: Avoid need for ugly setcpucontext() in HVM domain builder by
pre-setting the vcpu0 to runnable inside Xen, and have the builder
insert a JMP instruction to reach the hvmloader entry point from
address 0x0.
Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
---
tools/libxc/xc_hvm_build.c | 76 +++++++++++----------------------------------
xen/arch/x86/hvm/hvm.c | 6 +++
2 files changed, 25 insertions(+), 57 deletions(-)
diff -r 9eff4c97053b -r 772674585a1a tools/libxc/xc_hvm_build.c
--- a/tools/libxc/xc_hvm_build.c Mon Oct 01 14:11:15 2007 +0100
+++ b/tools/libxc/xc_hvm_build.c Mon Oct 01 15:12:05 2007 +0100
@@ -20,14 +20,6 @@
#include <xen/libelf.h>
#define SCRATCH_PFN 0xFFFFF
-
-/* Need to provide the right flavour of vcpu context for Xen */
-typedef union
-{
- vcpu_guest_context_x86_64_t c64;
- vcpu_guest_context_x86_32_t c32;
- vcpu_guest_context_t c;
-} vcpu_guest_context_either_t;
static void build_e820map(void *e820_page, unsigned long long mem_size)
{
@@ -154,12 +146,11 @@ static int loadelfimage(
static int setup_guest(int xc_handle,
uint32_t dom, int memsize,
- char *image, unsigned long image_size,
- vcpu_guest_context_either_t *ctxt)
+ char *image, unsigned long image_size)
{
xen_pfn_t *page_array = NULL;
unsigned long i, nr_pages = (unsigned long)memsize << (20 - PAGE_SHIFT);
- unsigned long shared_page_nr;
+ unsigned long shared_page_nr, entry_eip;
struct xen_add_to_physmap xatp;
struct shared_info *shared_info;
void *e820_page;
@@ -263,20 +254,20 @@ static int setup_guest(int xc_handle,
xc_set_hvm_param(xc_handle, dom, HVM_PARAM_BUFIOREQ_PFN, shared_page_nr-2);
xc_set_hvm_param(xc_handle, dom, HVM_PARAM_IOREQ_PFN, shared_page_nr);
+ /* Insert JMP <rel32> instruction at address 0x0 to reach entry point. */
+ entry_eip = elf_uval(&elf, elf.ehdr, e_entry);
+ if ( entry_eip != 0 )
+ {
+ char *page0 = xc_map_foreign_range(
+ xc_handle, dom, PAGE_SIZE, PROT_READ | PROT_WRITE, 0);
+ if ( page0 == NULL )
+ goto error_out;
+ page0[0] = 0xe9;
+ *(uint32_t *)&page0[1] = entry_eip - 5;
+ munmap(page0, PAGE_SIZE);
+ }
+
free(page_array);
-
- /* Set [er]ip in the way that's right for Xen */
- if ( strstr(caps, "x86_64") )
- {
- ctxt->c64.user_regs.rip = elf_uval(&elf, elf.ehdr, e_entry);
- ctxt->c64.flags = VGCF_online;
- }
- else
- {
- ctxt->c32.user_regs.eip = elf_uval(&elf, elf.ehdr, e_entry);
- ctxt->c32.flags = VGCF_online;
- }
-
return 0;
error_out:
@@ -290,42 +281,13 @@ static int xc_hvm_build_internal(int xc_
char *image,
unsigned long image_size)
{
- struct xen_domctl launch_domctl;
- vcpu_guest_context_either_t ctxt;
- int rc;
-
if ( (image == NULL) || (image_size == 0) )
{
ERROR("Image required");
- goto error_out;
- }
-
- memset(&ctxt, 0, sizeof(ctxt));
-
- if ( setup_guest(xc_handle, domid, memsize, image, image_size, &ctxt) < 0 )
- {
- goto error_out;
- }
-
- if ( lock_pages(&ctxt, sizeof(ctxt) ) )
- {
- PERROR("%s: ctxt mlock failed", __func__);
- goto error_out;
- }
-
- memset(&launch_domctl, 0, sizeof(launch_domctl));
- launch_domctl.domain = (domid_t)domid;
- launch_domctl.u.vcpucontext.vcpu = 0;
- set_xen_guest_handle(launch_domctl.u.vcpucontext.ctxt, &ctxt.c);
- launch_domctl.cmd = XEN_DOMCTL_setvcpucontext;
- rc = xc_domctl(xc_handle, &launch_domctl);
-
- unlock_pages(&ctxt, sizeof(ctxt));
-
- return rc;
-
- error_out:
- return -1;
+ return -1;
+ }
+
+ return setup_guest(xc_handle, domid, memsize, image, image_size);
}
static inline int is_loadable_phdr(Elf32_Phdr *phdr)
diff -r 9eff4c97053b -r 772674585a1a xen/arch/x86/hvm/hvm.c
--- a/xen/arch/x86/hvm/hvm.c Mon Oct 01 14:11:15 2007 +0100
+++ b/xen/arch/x86/hvm/hvm.c Mon Oct 01 15:12:05 2007 +0100
@@ -443,6 +443,8 @@ int hvm_vcpu_initialise(struct vcpu *v)
spin_lock_init(&v->arch.hvm_vcpu.tm_lock);
INIT_LIST_HEAD(&v->arch.hvm_vcpu.tm_list);
+ v->arch.guest_context.user_regs.eflags = 2;
+
if ( v->vcpu_id == 0 )
{
/* NB. All these really belong in hvm_domain_initialise(). */
@@ -453,6 +455,10 @@ int hvm_vcpu_initialise(struct vcpu *v)
/* Init guest TSC to start from zero. */
hvm_set_guest_time(v, 0);
+
+ /* Can start up without SIPI-SIPI or setvcpucontext domctl. */
+ v->is_initialised = 1;
+ clear_bit(_VPF_down, &v->pause_flags);
}
return 0;
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