AW: Kernel requires x86-64 CPU, after modifying arch_shared_info struct

[Jan Ruh <jan.ruh@xxxxxxxxxx>]

> Did you try backing up your changes and seeing if the same happens?

If backing up my changes everything works as expected.

> Did you rebuild both the Xen hypervisor and the tools?

Yes, I rebuild both Xen hypervisor and the tools.

> Pasting your xl config file would be helpful in order to help debug.

As requested my xl config:
    type="hvm"; extra="console=hvc0 earlyprintk=xen";
    kernel="/usr/lib/kernel/vmlinuz-domu";
    ramdisk="/usr/lib/kernel/initrd.img-domu";
    root="/dev/xvda2 ro";
    memory=1024;
    autoballoon="off";
    xen_platform_pci=1;
    pae=1; acpi=1; apic=1; vcpus=1;
    name="vm1";
    disk=["file:domu.img,hda,w"];
    vif=["bridge=xenbr0"];
    vfb=["type=vnc,keymap=de"];
    vnclisten="192.168.2.4:0";
    boot="c";'

> Posting your changes might also help spot something wonky.

diff --git a/xen/include/public/arch-x86/xen.h 
b/xen/include/public/arch-x86/xen.h
index 629cb2ba40..61c46504a5 100644
--- a/xen/include/public/arch-x86/xen.h
+++ b/xen/include/public/arch-x86/xen.h
@@ -265,6 +265,14 @@ struct arch_shared_info {
     /* There's no room for this field in the generic structure. */
     uint32_t wc_sec_hi;
 #endif
+
+    uint32_t st_version;
+    uint64_t time_sec;
+    uint64_t time_nsec;
+    uint64_t cycle_last;
+    uint32_t mult;
+    uint32_t shift;
+
 };
 typedef struct arch_shared_info arch_shared_info_t;

diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c
index c39fbe50a0..2782cb5127 100644
--- a/xen/arch/x86/time.c
+++ b/xen/arch/x86/time.c
@@ -1254,15 +1254,15 @@ void update_domain_synctime(struct domain *d)
 {
     uint32_t *st_version;

+    st_version = &shared_info(d, arch.st_version);
     *st_version = version_update_begin(*st_version);
     smp_wmb();

+    shared_info(d, arch.mult)        = global_time.mult;
+    shared_info(d, arch.shift)       = global_time.shift;
+    shared_info(d, arch.cycle_last)  = global_time.cycle_last;
+    shared_info(d, arch.time_sec)    = global_time.time_sec;
+    shared_info(d, arch.time_nsec)   = global_time.time_nsec;

     smp_wmb();
     *st_version = version_update_end(*st_version);

diff --git a/xen/common/sysctl.c b/xen/common/sysctl.c
index 72e7d33708..4b9ad0261b 100644
--- a/xen/common/sysctl.c
+++ b/xen/common/sysctl.c
@@ -503,22 +503,22 @@ long do_sysctl(XEN_GUEST_HANDLE_PARAM(xen_sysctl_t) 
u_sysctl)
     }
     case XEN_SYSCTL_adjust_gtime:
     {
+        struct adjust_gtime *adjust_gtime = (struct adjust_gtime*) 
&op->u.adjust_gtime;

+        ret = do_adj_gtime(adjust_gtime);
+
         copyback = 1;

         break;

diff --git a/tools/include/xen-foreign/reference.size 
b/tools/include/xen-foreign/reference.size
index bb2ada32fb..9afd11e5fa 100644
--- a/tools/include/xen-foreign/reference.size
+++ b/tools/include/xen-foreign/reference.size
@@ -9,6 +9,6 @@ vcpu_guest_context        |     344     344    2800    5168
 arch_vcpu_info            |       0       0      24      16
 vcpu_time_info            |      32      32      32      32
 vcpu_info                 |      48      48      64      64
-arch_shared_info          |       0       0      28      48
+arch_shared_info          |       0       0      64      88


global_time is a static struct in time.c, no existing Xen code is changed, just 
functions added that are being called from the sysctl adjust_gtime.

Further tests show that in /tools/libxc/xc_dom_binloader.c: 
xc_dom_parse_bin_kernel xc sets the dom->guest_type to "xen-3.0-x86_32" instead 
of "xen-3.0-x86_64". I also cannot see though how it can be connected to my 
change to arch_shared_info.

Sorry for the banner, I always forget that the mail client adds that thing, I 
hope it doesn't do it again.

Jan



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