diff options
| -rw-r--r-- | arch/x86/xen/mmu.c | 41 | ||||
| -rw-r--r-- | include/xen/interface/hvm/hvm_op.h | 19 |
2 files changed, 60 insertions, 0 deletions
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index 5a16824cc2b..963cb2df636 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 diff --git a/include/xen/interface/hvm/hvm_op.h b/include/xen/interface/hvm/hvm_op.h index a4827f46ee9..956a0468286 100644 --- a/include/xen/interface/hvm/hvm_op.h +++ b/include/xen/interface/hvm/hvm_op.h @@ -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__ */ |