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Revert "xen PVonHVM: use E820_Reserved area for shared_info"

This reverts commit 9d02b43dee.

We are doing this b/c on 32-bit PVonHVM with older hypervisors
(Xen 4.1) it ends up bothing up the start_info. This is bad b/c
we use it for the time keeping, and the timekeeping code loops
forever - as the version field never changes. Olaf says to
revert it, so lets do that.

Acked-by: Olaf Hering <>
Signed-off-by: Konrad Rzeszutek Wilk <>
This commit is contained in:
Konrad Rzeszutek Wilk 2013-02-14 21:29:31 -05:00
parent 5eb65be2d9
commit e9daff24a2
3 changed files with 24 additions and 55 deletions

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@ -1517,72 +1517,51 @@ asmlinkage void __init xen_start_kernel(void)
static struct shared_info *xen_hvm_shared_info;
static unsigned long xen_hvm_sip_phys;
static int xen_major, xen_minor;
static void xen_hvm_connect_shared_info(unsigned long pfn)
void __ref xen_hvm_init_shared_info(void)
int cpu;
struct xen_add_to_physmap xatp;
static struct shared_info *shared_info_page = 0;
if (!shared_info_page)
shared_info_page = (struct shared_info *)
extend_brk(PAGE_SIZE, PAGE_SIZE);
xatp.domid = DOMID_SELF;
xatp.idx = 0; = XENMAPSPACE_shared_info;
xatp.gpfn = pfn;
xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
static void __init xen_hvm_set_shared_info(struct shared_info *sip)
int cpu;
HYPERVISOR_shared_info = sip;
HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
/* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
* page, we use it in the event channel upcall and in some pvclock
* related functions. We don't need the vcpu_info placement
* optimizations because we don't use any pv_mmu or pv_irq op on
* HVM. */
* HVM.
* When xen_hvm_init_shared_info is run at boot time only vcpu 0 is
* online but xen_hvm_init_shared_info is run at resume time too and
* in that case multiple vcpus might be online. */
for_each_online_cpu(cpu) {
per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
/* Reconnect the shared_info pfn to a (new) mfn */
void xen_hvm_resume_shared_info(void)
xen_hvm_connect_shared_info(xen_hvm_sip_phys >> PAGE_SHIFT);
/* Xen tools prior to Xen 4 do not provide a E820_Reserved area for guest usage.
* On these old tools the shared info page will be placed in E820_Ram.
* Xen 4 provides a E820_Reserved area at 0xFC000000, and this code expects
* that nothing is mapped up to HVM_SHARED_INFO_ADDR.
* Xen 4.3+ provides an explicit 1MB area at HVM_SHARED_INFO_ADDR which is used
* here for the shared info page. */
static void __init xen_hvm_init_shared_info(void)
if (xen_major < 4) {
xen_hvm_shared_info = extend_brk(PAGE_SIZE, PAGE_SIZE);
xen_hvm_sip_phys = __pa(xen_hvm_shared_info);
} else {
xen_hvm_sip_phys = HVM_SHARED_INFO_ADDR;
set_fixmap(FIX_PARAVIRT_BOOTMAP, xen_hvm_sip_phys);
xen_hvm_shared_info =
(struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
xen_hvm_connect_shared_info(xen_hvm_sip_phys >> PAGE_SHIFT);
static void __init init_hvm_pv_info(void)
int major, minor;
uint32_t eax, ebx, ecx, edx, pages, msr, base;
u64 pfn;
base = xen_cpuid_base();
cpuid(base + 1, &eax, &ebx, &ecx, &edx);
major = eax >> 16;
minor = eax & 0xffff;
printk(KERN_INFO "Xen version %d.%d.\n", major, minor);
cpuid(base + 2, &pages, &msr, &ecx, &edx);
pfn = __pa(hypercall_page);
@ -1633,22 +1612,12 @@ static void __init xen_hvm_guest_init(void)
static bool __init xen_hvm_platform(void)
uint32_t eax, ebx, ecx, edx, base;
if (xen_pv_domain())
return false;
base = xen_cpuid_base();
if (!base)
if (!xen_cpuid_base())
return false;
cpuid(base + 1, &eax, &ebx, &ecx, &edx);
xen_major = eax >> 16;
xen_minor = eax & 0xffff;
printk(KERN_INFO "Xen version %d.%d.\n", xen_major, xen_minor);
return true;

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@ -30,7 +30,7 @@ void xen_arch_hvm_post_suspend(int suspend_cancelled)
int cpu;
if (xen_feature(XENFEAT_hvm_safe_pvclock)) {

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@ -40,7 +40,7 @@ void xen_enable_syscall(void);
void xen_vcpu_restore(void);
void xen_callback_vector(void);
void xen_hvm_resume_shared_info(void);
void xen_hvm_init_shared_info(void);
void xen_unplug_emulated_devices(void);
void __init xen_build_dynamic_phys_to_machine(void);