Commit ccff9b1d authored by Linus Torvalds's avatar Linus Torvalds

Merge tag 'stable/for-linus-3.7-rc0-tag' of...

Merge tag 'stable/for-linus-3.7-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

Pull Xen fixes from Konrad Rzeszutek Wilk:
 "This has four bug-fixes and one tiny feature that I forgot to put
  initially in my tree due to oversight.

  The feature is for kdump kernels to speed up the /proc/vmcore reading.
  There is a ram_is_pfn helper function that the different platforms can
  register for.  We are now doing that.

  The bug-fixes cover some embarrassing struct pv_cpu_ops variables
  being set to NULL on Xen (but not baremetal).  We had a similar issue
  in the past with {write|read}_msr_safe and this fills the three
  missing ones.  The other bug-fix is to make the console output (hvc)
  be capable of dealing with misbehaving backends and not fall flat on
  its face.  Lastly, a quirk for older XenBus implementations that came
  with an ancient v3.4 hypervisor (so RHEL5 based) - reading of certain
  non-existent attributes just hangs the guest during bootup - so we
  take precaution of not doing that on such older installations.

  Feature:
   - Register a pfn_is_ram helper to speed up reading of /proc/vmcore.
  Bug-fixes:
   - Three pvops call for Xen were undefined causing BUG_ONs.
   - Add a quirk so that the shutdown watches (used by kdump) are not
     used with older Xen (3.4).
   - Fix ungraceful state transition for the HVC console."

* tag 'stable/for-linus-3.7-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/pv-on-hvm kexec: add quirk for Xen 3.4 and shutdown watches.
  xen/bootup: allow {read|write}_cr8 pvops call.
  xen/bootup: allow read_tscp call for Xen PV guests.
  xen pv-on-hvm: add pfn_is_ram helper for kdump
  xen/hvc: handle backend CLOSED without CLOSING
parents 3dc329ba cb6b6df1
......@@ -987,7 +987,16 @@ static void xen_write_cr4(unsigned long cr4)
native_write_cr4(cr4);
}
#ifdef CONFIG_X86_64
static inline unsigned long xen_read_cr8(void)
{
return 0;
}
static inline void xen_write_cr8(unsigned long val)
{
BUG_ON(val);
}
#endif
static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
{
int ret;
......@@ -1156,6 +1165,11 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst = {
.read_cr4_safe = native_read_cr4_safe,
.write_cr4 = xen_write_cr4,
#ifdef CONFIG_X86_64
.read_cr8 = xen_read_cr8,
.write_cr8 = xen_write_cr8,
#endif
.wbinvd = native_wbinvd,
.read_msr = native_read_msr_safe,
......@@ -1164,6 +1178,8 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst = {
.read_tsc = native_read_tsc,
.read_pmc = native_read_pmc,
.read_tscp = native_read_tscp,
.iret = xen_iret,
.irq_enable_sysexit = xen_sysexit,
#ifdef CONFIG_X86_64
......
......@@ -47,6 +47,7 @@
#include <linux/gfp.h>
#include <linux/memblock.h>
#include <linux/seq_file.h>
#include <linux/crash_dump.h>
#include <trace/events/xen.h>
......@@ -2381,6 +2382,43 @@ void xen_destroy_contiguous_region(unsigned long vstart, unsigned int order)
EXPORT_SYMBOL_GPL(xen_destroy_contiguous_region);
#ifdef CONFIG_XEN_PVHVM
#ifdef CONFIG_PROC_VMCORE
/*
* This function is used in two contexts:
* - the kdump kernel has to check whether a pfn of the crashed kernel
* was a ballooned page. vmcore is using this function to decide
* whether to access a pfn of the crashed kernel.
* - the kexec kernel has to check whether a pfn was ballooned by the
* previous kernel. If the pfn is ballooned, handle it properly.
* Returns 0 if the pfn is not backed by a RAM page, the caller may
* handle the pfn special in this case.
*/
static int xen_oldmem_pfn_is_ram(unsigned long pfn)
{
struct xen_hvm_get_mem_type a = {
.domid = DOMID_SELF,
.pfn = pfn,
};
int ram;
if (HYPERVISOR_hvm_op(HVMOP_get_mem_type, &a))
return -ENXIO;
switch (a.mem_type) {
case HVMMEM_mmio_dm:
ram = 0;
break;
case HVMMEM_ram_rw:
case HVMMEM_ram_ro:
default:
ram = 1;
break;
}
return ram;
}
#endif
static void xen_hvm_exit_mmap(struct mm_struct *mm)
{
struct xen_hvm_pagetable_dying a;
......@@ -2411,6 +2449,9 @@ void __init xen_hvm_init_mmu_ops(void)
{
if (is_pagetable_dying_supported())
pv_mmu_ops.exit_mmap = xen_hvm_exit_mmap;
#ifdef CONFIG_PROC_VMCORE
register_oldmem_pfn_is_ram(&xen_oldmem_pfn_is_ram);
#endif
}
#endif
......
......@@ -478,7 +478,6 @@ static void xencons_backend_changed(struct xenbus_device *dev,
case XenbusStateInitialising:
case XenbusStateInitialised:
case XenbusStateUnknown:
case XenbusStateClosed:
break;
case XenbusStateInitWait:
......@@ -488,6 +487,10 @@ static void xencons_backend_changed(struct xenbus_device *dev,
xenbus_switch_state(dev, XenbusStateConnected);
break;
case XenbusStateClosed:
if (dev->state == XenbusStateClosed)
break;
/* Missed the backend's CLOSING state -- fallthrough */
case XenbusStateClosing:
xenbus_frontend_closed(dev);
break;
......
......@@ -48,6 +48,7 @@
#include <xen/xenbus.h>
#include <xen/xen.h>
#include "xenbus_comms.h"
#include <asm/xen/hypervisor.h>
struct xs_stored_msg {
struct list_head list;
......@@ -618,7 +619,24 @@ static struct xenbus_watch *find_watch(const char *token)
return NULL;
}
/*
* Certain older XenBus toolstack cannot handle reading values that are
* not populated. Some Xen 3.4 installation are incapable of doing this
* so if we are running on anything older than 4 do not attempt to read
* control/platform-feature-xs_reset_watches.
*/
static bool xen_strict_xenbus_quirk()
{
uint32_t eax, ebx, ecx, edx, base;
base = xen_cpuid_base();
cpuid(base + 1, &eax, &ebx, &ecx, &edx);
if ((eax >> 16) < 4)
return true;
return false;
}
static void xs_reset_watches(void)
{
int err, supported = 0;
......@@ -626,6 +644,9 @@ static void xs_reset_watches(void)
if (!xen_hvm_domain() || xen_initial_domain())
return;
if (xen_strict_xenbus_quirk())
return;
err = xenbus_scanf(XBT_NIL, "control",
"platform-feature-xs_reset_watches", "%d", &supported);
if (err != 1 || !supported)
......
......@@ -43,4 +43,23 @@ struct xen_hvm_pagetable_dying {
typedef struct xen_hvm_pagetable_dying xen_hvm_pagetable_dying_t;
DEFINE_GUEST_HANDLE_STRUCT(xen_hvm_pagetable_dying_t);
enum hvmmem_type_t {
HVMMEM_ram_rw, /* Normal read/write guest RAM */
HVMMEM_ram_ro, /* Read-only; writes are discarded */
HVMMEM_mmio_dm, /* Reads and write go to the device model */
};
#define HVMOP_get_mem_type 15
/* Return hvmmem_type_t for the specified pfn. */
struct xen_hvm_get_mem_type {
/* Domain to be queried. */
domid_t domid;
/* OUT variable. */
uint16_t mem_type;
uint16_t pad[2]; /* align next field on 8-byte boundary */
/* IN variable. */
uint64_t pfn;
};
DEFINE_GUEST_HANDLE_STRUCT(xen_hvm_get_mem_type);
#endif /* __XEN_PUBLIC_HVM_HVM_OP_H__ */
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