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
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index bf788d3..e3497f2 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -987,7 +987,16 @@
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 @@
.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 @@
.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
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index fd28d86..6226c99 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -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 @@
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 @@
{
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
diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
index 2944ff8..f4abfe2 100644
--- a/drivers/tty/hvc/hvc_xen.c
+++ b/drivers/tty/hvc/hvc_xen.c
@@ -478,7 +478,6 @@
case XenbusStateInitialising:
case XenbusStateInitialised:
case XenbusStateUnknown:
- case XenbusStateClosed:
break;
case XenbusStateInitWait:
@@ -488,6 +487,10 @@
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;
diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c
index 131dec0..48220e1 100644
--- a/drivers/xen/xenbus/xenbus_xs.c
+++ b/drivers/xen/xenbus/xenbus_xs.c
@@ -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 @@
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 @@
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)
diff --git a/include/xen/interface/hvm/hvm_op.h b/include/xen/interface/hvm/hvm_op.h
index a4827f4..956a046 100644
--- a/include/xen/interface/hvm/hvm_op.h
+++ b/include/xen/interface/hvm/hvm_op.h
@@ -43,4 +43,23 @@
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__ */
