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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 02:56:35 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 02:56:35 +0000 |
commit | eba0cfa6b0bef4f2e73c8630a7efa3944df8b0f8 (patch) | |
tree | 74c37eede1f0634cc5de1c63c934edaa1630c6bc /kexec/crashdump-xen.c | |
parent | Initial commit. (diff) | |
download | kexec-tools-eba0cfa6b0bef4f2e73c8630a7efa3944df8b0f8.tar.xz kexec-tools-eba0cfa6b0bef4f2e73c8630a7efa3944df8b0f8.zip |
Adding upstream version 1:2.0.27.upstream/1%2.0.27upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'kexec/crashdump-xen.c')
-rw-r--r-- | kexec/crashdump-xen.c | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/kexec/crashdump-xen.c b/kexec/crashdump-xen.c new file mode 100644 index 0000000..3f59a0d --- /dev/null +++ b/kexec/crashdump-xen.c @@ -0,0 +1,256 @@ +#define _GNU_SOURCE +#include <stdio.h> +#include <stdarg.h> +#include <string.h> +#include <stdlib.h> +#include <elf.h> +#include <errno.h> +#include <limits.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <unistd.h> +#include <fcntl.h> +#include <setjmp.h> +#include <signal.h> +#include "kexec.h" +#include "crashdump.h" +#include "kexec-syscall.h" +#include "config.h" +#include "kexec-xen.h" + +struct crash_note_info { + unsigned long base; + unsigned long length; +}; + +static int xen_phys_cpus; +static struct crash_note_info *xen_phys_notes; + +/* based on code from xen-detect.c */ +static int is_dom0; +#if defined(__i386__) || defined(__x86_64__) +static jmp_buf xen_sigill_jmp; +void xen_sigill_handler(int sig) +{ + longjmp(xen_sigill_jmp, 1); +} + +static void xen_cpuid(uint32_t idx, uint32_t *regs, int pv_context) +{ +#ifdef __i386__ + /* Use the stack to avoid reg constraint failures with some gcc flags */ + asm volatile ( + "push %%eax; push %%ebx; push %%ecx; push %%edx\n\t" + "test %1,%1 ; jz 1f ; ud2a ; .ascii \"xen\" ; 1: cpuid\n\t" + "mov %%eax,(%2); mov %%ebx,4(%2)\n\t" + "mov %%ecx,8(%2); mov %%edx,12(%2)\n\t" + "pop %%edx; pop %%ecx; pop %%ebx; pop %%eax\n\t" + : : "a" (idx), "c" (pv_context), "S" (regs) : "memory" ); +#else + asm volatile ( + "test %5,%5 ; jz 1f ; ud2a ; .ascii \"xen\" ; 1: cpuid\n\t" + : "=a" (regs[0]), "=b" (regs[1]), "=c" (regs[2]), "=d" (regs[3]) + : "0" (idx), "1" (pv_context), "2" (0) ); +#endif +} + +static int check_for_xen(int pv_context) +{ + uint32_t regs[4]; + char signature[13]; + uint32_t base; + + for (base = 0x40000000; base < 0x40010000; base += 0x100) + { + xen_cpuid(base, regs, pv_context); + + *(uint32_t *)(signature + 0) = regs[1]; + *(uint32_t *)(signature + 4) = regs[2]; + *(uint32_t *)(signature + 8) = regs[3]; + signature[12] = '\0'; + + if (strcmp("XenVMMXenVMM", signature) == 0 && regs[0] >= (base + 2)) + goto found; + } + + return 0; + +found: + xen_cpuid(base + 1, regs, pv_context); + return regs[0]; +} + +static int xen_detect_pv_guest(void) +{ + struct sigaction act, oldact; + int is_pv = -1; + + if (setjmp(xen_sigill_jmp)) + return is_pv; + + memset(&act, 0, sizeof(act)); + act.sa_handler = xen_sigill_handler; + sigemptyset (&act.sa_mask); + if (sigaction(SIGILL, &act, &oldact)) + return is_pv; + if (check_for_xen(1)) + is_pv = 1; + sigaction(SIGILL, &oldact, NULL); + return is_pv; +} +#else +static int xen_detect_pv_guest(void) +{ + return 1; +} +#endif + +/* + * Return 1 if its a PV guest. + * This includes dom0, which is the only PV guest where kexec/kdump works. + * HVM guests have to be handled as native hardware. + */ +int xen_present(void) +{ + if (!is_dom0) { + if (access("/proc/xen", F_OK) == 0) + is_dom0 = xen_detect_pv_guest(); + else + is_dom0 = -1; + } + return is_dom0 > 0; +} + +unsigned long xen_architecture(struct crash_elf_info *elf_info) +{ + unsigned long machine = elf_info->machine; +#ifdef HAVE_LIBXENCTRL + int rc; + xen_capabilities_info_t capabilities; + xc_interface *xc; + + if (!xen_present()) + goto out; + + memset(capabilities, '0', XEN_CAPABILITIES_INFO_LEN); + + xc = xc_interface_open(NULL, NULL, 0); + if ( !xc ) { + fprintf(stderr, "failed to open xen control interface.\n"); + goto out; + } + + rc = xc_version(xc, XENVER_capabilities, &capabilities[0]); + if ( rc == -1 ) { + fprintf(stderr, "failed to make Xen version hypercall.\n"); + goto out_close; + } + + if (strstr(capabilities, "xen-3.0-x86_64")) + machine = EM_X86_64; + else if (strstr(capabilities, "xen-3.0-x86_32")) + machine = EM_386; + + out_close: + xc_interface_close(xc); + + out: +#endif + return machine; +} + +#ifdef HAVE_LIBXENCTRL +int get_xen_vmcoreinfo(uint64_t *addr, uint64_t *len) +{ + uint64_t end; + int ret = 0; + + ret = xen_get_kexec_range(KEXEC_RANGE_MA_VMCOREINFO, addr, &end); + if (ret < 0) + return -1; + + *len = end - *addr + 1; + + return 0; +} + +int xen_get_nr_phys_cpus(void) +{ + xc_interface *xc; + int max_cpus; + int cpu = -1; + + if (xen_phys_cpus) + return xen_phys_cpus; + + xc = xc_interface_open(NULL, NULL, 0); + if (!xc) { + fprintf(stderr, "failed to open xen control interface.\n"); + return -1; + } + + max_cpus = xc_get_max_cpus(xc); + if (max_cpus <= 0) + goto out; + + xen_phys_notes = calloc(max_cpus, sizeof(*xen_phys_notes)); + if (xen_phys_notes == NULL) + goto out; + + for (cpu = 0; cpu < max_cpus; cpu++) { + uint64_t size, start; + int ret; + + ret = xc_kexec_get_range(xc, KEXEC_RANGE_MA_CPU, cpu, &size, &start); + if (ret < 0) + break; + + xen_phys_notes[cpu].base = start; + xen_phys_notes[cpu].length = size; + } + + xen_phys_cpus = cpu; + +out: + xc_interface_close(xc); + return cpu; +} +#else +int get_xen_vmcoreinfo(uint64_t *addr, uint64_t *len) +{ + return -1; +} + +int xen_get_nr_phys_cpus(void) +{ + return -1; +} +#endif + + +int xen_get_note(int cpu, uint64_t *addr, uint64_t *len) +{ + struct crash_note_info *note; + + if (xen_phys_cpus <= 0) + return -1; + + note = xen_phys_notes + cpu; + + *addr = note->base; + *len = note->length; + + return 0; +} + +#ifdef HAVE_LIBXENCTRL +int xen_get_crashkernel_region(uint64_t *start, uint64_t *end) +{ + return xen_get_kexec_range(KEXEC_RANGE_MA_CRASH, start, end); +} +#else +int xen_get_crashkernel_region(uint64_t *start, uint64_t *end) +{ + return -1; +} +#endif |