Revert the PVonHVM kexec. The patch introduces a regression

with older hypervisor stacks, such as Xen 4.1.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.13 (GNU/Linux)
 
 iQEcBAABAgAGBQJRHZ7eAAoJEFjIrFwIi8fJZ+sH/ieMkzdBB6aqbFMcNr7mkfBo
 i3swjO2JQI7REYIHfKEVoR3IgHfqKEuABdeEQrceE0XqDepFh84YiKGI2QpPRWEA
 903vUV4DXVdcBrypbL45tSFZ1Jxsrzx+F7WfV/f9WHyeiwOyaZTGVQH0VuOzpcum
 RvPTT7MmC7g8MJDi66SDYBaX/pBQzifQ81nMWWjXNw0w4CwWX7le1cScZEP42MR6
 jTEHzYMLDojdO+2aQM5pt/0CGI5tzBHtX5nNRl6tovlPI3ckknYYx6a7RfxkfZzF
 IkMIuGS32yLfsswPPIiMs47/Qgiq3BN6eSTJXMZKUwQokL9yEs8LodcnRDYfgyQ=
 =fqcJ
 -----END PGP SIGNATURE-----

Merge tag 'stable/for-linus-3.8-rc7-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

Pull xen fixes from Konrad Rzeszutek Wilk:
 "Two fixes:

   - A simple bug-fix for redundant NULL check.

   - CVE-2013-0228/XSA-42: x86/xen: don't assume %ds is usable in
     xen_iret for 32-bit PVOPS

  and two reverts:

   - Revert the PVonHVM kexec.  The patch introduces a regression with
     older hypervisor stacks, such as Xen 4.1."

* tag 'stable/for-linus-3.8-rc7-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  Revert "xen PVonHVM: use E820_Reserved area for shared_info"
  Revert "xen/PVonHVM: fix compile warning in init_hvm_pv_info"
  xen: remove redundant NULL check before unregister_and_remove_pcpu().
  x86/xen: don't assume %ds is usable in xen_iret for 32-bit PVOPS.
This commit is contained in:
Linus Torvalds 2013-02-15 12:12:55 -08:00
commit f741656d64
5 changed files with 33 additions and 65 deletions

View File

@ -1517,72 +1517,51 @@ asmlinkage void __init xen_start_kernel(void)
#endif
}
#ifdef CONFIG_XEN_PVHVM
#define HVM_SHARED_INFO_ADDR 0xFE700000UL
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;
xatp.space = XENMAPSPACE_shared_info;
xatp.gpfn = pfn;
xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
BUG();
}
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. */
for_each_online_cpu(cpu)
* 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);
xen_hvm_set_shared_info(xen_hvm_shared_info);
}
#ifdef CONFIG_XEN_PVHVM
static void __init init_hvm_pv_info(void)
{
uint32_t ecx, edx, pages, msr, base;
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;
}

View File

@ -30,7 +30,7 @@ void xen_arch_hvm_post_suspend(int suspend_cancelled)
{
#ifdef CONFIG_XEN_PVHVM
int cpu;
xen_hvm_resume_shared_info();
xen_hvm_init_shared_info();
xen_callback_vector();
xen_unplug_emulated_devices();
if (xen_feature(XENFEAT_hvm_safe_pvclock)) {

View File

@ -89,11 +89,11 @@ ENTRY(xen_iret)
*/
#ifdef CONFIG_SMP
GET_THREAD_INFO(%eax)
movl TI_cpu(%eax), %eax
movl __per_cpu_offset(,%eax,4), %eax
mov xen_vcpu(%eax), %eax
movl %ss:TI_cpu(%eax), %eax
movl %ss:__per_cpu_offset(,%eax,4), %eax
mov %ss:xen_vcpu(%eax), %eax
#else
movl xen_vcpu, %eax
movl %ss:xen_vcpu, %eax
#endif
/* check IF state we're restoring */
@ -106,11 +106,11 @@ ENTRY(xen_iret)
* resuming the code, so we don't have to be worried about
* being preempted to another CPU.
*/
setz XEN_vcpu_info_mask(%eax)
setz %ss:XEN_vcpu_info_mask(%eax)
xen_iret_start_crit:
/* check for unmasked and pending */
cmpw $0x0001, XEN_vcpu_info_pending(%eax)
cmpw $0x0001, %ss:XEN_vcpu_info_pending(%eax)
/*
* If there's something pending, mask events again so we can
@ -118,7 +118,7 @@ xen_iret_start_crit:
* touch XEN_vcpu_info_mask.
*/
jne 1f
movb $1, XEN_vcpu_info_mask(%eax)
movb $1, %ss:XEN_vcpu_info_mask(%eax)
1: popl %eax

View File

@ -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);

View File

@ -278,8 +278,7 @@ static int sync_pcpu(uint32_t cpu, uint32_t *max_cpu)
* Only those at cpu present map has its sys interface.
*/
if (info->flags & XEN_PCPU_FLAGS_INVALID) {
if (pcpu)
unregister_and_remove_pcpu(pcpu);
unregister_and_remove_pcpu(pcpu);
return 0;
}