From c2a8238a2c1e37a2ae6d628a2b7bd95d1b5f1a89 Mon Sep 17 00:00:00 2001 From: Stefan Weil Date: Mon, 31 Oct 2011 21:29:46 +0100 Subject: Support running QEMU on Valgrind Valgrind is a tool which can automatically detect many kinds of bugs. Running QEMU on Valgrind with x86_64 hosts was not possible because Valgrind aborts when memalign is called with an alignment larger than 1 MiB. QEMU normally uses 2 MiB on Linux x86_64. Now the alignment is reduced to the page size when QEMU is running on Valgrind. v2: Instead of using the macro RUNNING_ON_VALGRIND from valgrind.h, the patch now uses a hack from libvirt which tests for the pre-loaded vgpreload_*.so shared libraries. This avoids the need for valgrind.h. Signed-off-by: Stefan Weil Signed-off-by: Anthony Liguori --- oslib-posix.c | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-) (limited to 'oslib-posix.c') diff --git a/oslib-posix.c b/oslib-posix.c index dbc8ee8..6f29762 100644 --- a/oslib-posix.c +++ b/oslib-posix.c @@ -36,8 +36,11 @@ extern int daemon(int, int); #endif #if defined(__linux__) && defined(__x86_64__) - /* Use 2MB alignment so transparent hugepages can be used by KVM */ + /* Use 2 MiB alignment so transparent hugepages can be used by KVM. + Valgrind does not support alignments larger than 1 MiB, + therefore we need special code which handles running on Valgrind. */ # define QEMU_VMALLOC_ALIGN (512 * 4096) +# define CONFIG_VALGRIND #else # define QEMU_VMALLOC_ALIGN getpagesize() #endif @@ -47,7 +50,11 @@ extern int daemon(int, int); #include "trace.h" #include "qemu_socket.h" - +#if defined(CONFIG_VALGRIND) +static int running_on_valgrind = -1; +#else +# define running_on_valgrind 0 +#endif int qemu_daemon(int nochdir, int noclose) { @@ -89,7 +96,16 @@ void *qemu_vmalloc(size_t size) void *ptr; size_t align = QEMU_VMALLOC_ALIGN; - if (size < align) { +#if defined(CONFIG_VALGRIND) + if (running_on_valgrind < 0) { + /* First call, test whether we are running on Valgrind. + This is a substitute for RUNNING_ON_VALGRIND from valgrind.h. */ + const char *ld = getenv("LD_PRELOAD"); + running_on_valgrind = (ld != NULL && strstr(ld, "vgpreload")); + } +#endif + + if (size < align || running_on_valgrind) { align = getpagesize(); } ptr = qemu_memalign(align, size); -- cgit v1.1