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author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-12 15:20:28 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-12 15:20:28 +0200 |
commit | ccff9b1db693062b0a9c9070f4304deb47ef215c (patch) | |
tree | a956cc800a03f11254105fbd9926bab537b6863f /arch/x86/xen/mmu.c | |
parent | Merge branch 'slab/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/p... (diff) | |
parent | xen/pv-on-hvm kexec: add quirk for Xen 3.4 and shutdown watches. (diff) | |
download | linux-ccff9b1db693062b0a9c9070f4304deb47ef215c.tar.xz linux-ccff9b1db693062b0a9c9070f4304deb47ef215c.zip |
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
Diffstat (limited to 'arch/x86/xen/mmu.c')
-rw-r--r-- | arch/x86/xen/mmu.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index fd28d86fe3d2..6226c99729b9 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 @@ 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 |