diff options
Diffstat (limited to 'zarb-ml/mageia-dev/attachments/20120109/d93f433f/attachment-0003.obj')
| -rw-r--r-- | zarb-ml/mageia-dev/attachments/20120109/d93f433f/attachment-0003.obj | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/zarb-ml/mageia-dev/attachments/20120109/d93f433f/attachment-0003.obj b/zarb-ml/mageia-dev/attachments/20120109/d93f433f/attachment-0003.obj new file mode 100644 index 000000000..2bd391f8b --- /dev/null +++ b/zarb-ml/mageia-dev/attachments/20120109/d93f433f/attachment-0003.obj @@ -0,0 +1,93 @@ +c::is_xen() use cpuid in order to detect we're under XEN + +diff -up ./c/stuff.xs.pl.tv2 ./c/stuff.xs.pl +--- ./c/stuff.xs.pl.tv2 2012-01-09 10:49:22.807894338 +0100 ++++ ./c/stuff.xs.pl 2012-01-09 11:03:04.124482279 +0100 +@@ -105,6 +105,40 @@ int length_of_space_padded(char *str, in + return len; + } + ++int pv_context; ++static void cpuid(uint32_t idx, ++ uint32_t *eax, ++ uint32_t *ebx, ++ uint32_t *ecx, ++ uint32_t *edx) ++{ ++ asm volatile ( ++ "test %1,%1 ; jz 1f ; ud2a ; .ascii \"xen\" ; 1: cpuid" ++ : "=a" (*eax), "=b" (*ebx), "=c" (*ecx), "=d" (*edx) ++ : "0" (idx), "1" (pv_context) ); ++} ++ ++static int check_for_xen(void) ++{ ++ uint32_t eax, ebx, ecx, edx; ++ char signature[13]; ++ ++ cpuid(0x40000000, &eax, &ebx, &ecx, &edx); ++ *(uint32_t *)(signature + 0) = ebx; ++ *(uint32_t *)(signature + 4) = ecx; ++ *(uint32_t *)(signature + 8) = edx; ++ signature[12] = ' . "'\0'" . '; ++ ++ if ( strcmp("XenVMMXenVMM", signature) || (eax < 0x40000002) ) ++ return 0; ++ ++ cpuid(0x40000001, &eax, &ebx, &ecx, &edx); ++ printf("Running in %s context on Xen v%d.%d.\n", ++ pv_context ? "PV" : "HVM", (uint16_t)(eax >> 16), (uint16_t)eax); ++ return 1; ++} ++ ++ + MODULE = c::stuff PACKAGE = c::stuff + + '; +@@ -116,6 +150,46 @@ pcmcia_probe() + + print ' + int ++is_xen() ++ CODE: ++ pid_t pid; ++ int status; ++ uint32_t dummy; ++ ++ /* Check for execution in HVM context. */ ++ if ( check_for_xen() ) ++ return 0; ++ ++ /* Now we check for execution in PV context. */ ++ pv_context = 1; ++ ++ /* ++ * Fork a child to test the paravirtualised CPUID instruction. ++ * If executed outside Xen PV context, the extended opcode will fault. ++ */ ++ pid = fork(); ++ switch ( pid ) ++ { ++ case 0: ++ /* Child: test paravirtualised CPUID opcode and then exit cleanly. */ ++ cpuid(0x40000000, &dummy, &dummy, &dummy, &dummy); ++ exit(0); ++ case -1: ++ fprintf(stderr, "Fork failed.\n"); ++ return 0; ++ } ++ ++ /* ++ * Parent waits for child to terminate and checks for clean exit. ++ * Only if the exit is clean is it safe for us to try the extended CPUID. ++ */ ++ waitpid(pid, &status, 0); ++ if ( WIFEXITED(status) && check_for_xen() ) ++ return 0; ++ ++ return 0; ++ ++int + del_partition(hd, part_number) + int hd + int part_number
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