<div dir="ltr">Dave asked for a different commit message that describes the problem a bit better: anv: Suffix the intel_icd file with the host CPU Vulkan has a multi-arch problem... The idea behind the Vulkan loader is that you have a little json file on your disk that tells the loader where to find drivers. The loader looks for these json files in standard locations, and then goes and loads the my_driver.so's that they specify. This allows you as a driver implementer to put their driver wherever on the disk they want so long as the ICD points in the right place. For a multi-arch system, however, you may have multiple libvulkan_intel.so files installed that the loader needs to pick depending on architecture. Since the ICD file format does not specify any architecture information, you can't tell the loader where to find the 32-bit version vs. the 64-bit version. The way that packagers have been dealing with this is to place libvulkan_intel.so in the top level lib directory and provide just a name (and no path) to the loader. It will then use the regular system search paths and find the correct driver. While this solution works fine for distro-installed Vulkan drivers, it doesn't work so well for user-installed drivers because they may put it in /usr/local or $HOME/.local or some other more exotic location. In this case, you can't use an ICD json file with just a library name because it doesn't know where to find it; you also have to add that to your library lookup path via LD_LIBRARY_PATH or similar. This patch handles both use-cases by taking advantage of the fact that the loader dlopen()s each of the drivers and, if one dlopen() calls fails, it silently continues on to open other drivers. By suffixing the icd file, we can provide two different json files: intel_icd.x86_64.json and intel_icd.i686.json with different paths. Since dlopen() will only succeed on the libvulkan_intel.so of the right arch, the loader will happily ignore the others and load that one. This allows us to properly handle multi-arch while still providing a full path so user installs will work fine. I tested this on my Fedora 25 machine with 32 and 64-bit builds of our Vulkan driver installed and 32 and 64-bit builds of crucible. It seems to work just fine. <div class="gmail_extra"> <div class="gmail_quote">On Thu, Oct 20, 2016 at 4:04 PM, Jason Ekstrand <<a href="mailto:jason@jlekstrand.net" target="_blank">jason@jlekstrand.net</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Vulkan has a multi-arch problem... The idea behind the Vulkan loader is that you have a little json file on your disk that tells the loader where to find drivers. The loader looks for these json files in standard locations, and then goes and loads the my_driver.so's that they specify. This allows you as a driver implementer to put their driver wherever on the disk they want so long as the icd points in the right place. Unfortunately, this system was not designed with multi-arch in mind. Instead of having some way to tell the loader "here's the 32-bit version" or "here's the 64-bit version", you give the loader a single .so. This means that if you install globally, your icd file somehow has to magically point at both /usr/lib/libvulkan_intel.so and /usr/lib64/libvulkan_intel.so on a multi-arch system. If you use an absolute path, this is a problem because the 32 and 64-bit versions of the packages stomp each other. This patch solves this problem by taking advantage of the fact that the loader dlopen()s each of the drivers and, if one dlopen() calls fails, it silently continues on to open other drivers. By suffixing the icd file, we can provide two different json files: intel_icd.x86_64.json and intel_icd.i686.json with different paths. Since dlopen() will only succeed on the libvulkan_intel.so of the right arch, the loader will happily ignore the others and load that one. I tested this on my Fedora 25 machine with 32 and 64-bit builds of our Vulkan driver installed and 32 and 64-bit builds of crucible. It seems to work just fine. Signed-off-by: Jason Ekstrand <<a href="mailto:jason@jlekstrand.net" target="_blank">jason@jlekstrand.net</a>> Cc: Matt Turner <<a href="mailto:mattst88@gmail.com" target="_blank">mattst88@gmail.com</a>> Cc: Emil Velikov <<a href="mailto:emil.velikov@collabora.com" target="_blank">emil.velikov@collabora.com</a>> Cc: Adam Jackson <<a href="mailto:ajax@redhat.com" target="_blank">ajax@redhat.com</a>> Cc: Timo Aaltonen <<a href="mailto:tjaalton@ubuntu.com" target="_blank">tjaalton@ubuntu.com</a>> Cc: Dave Airlie <<a href="mailto:airlied@redhat.com" target="_blank">airlied@redhat.com</a>> --- src/intel/vulkan/Makefile.am | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/intel/vulkan/Makefile.am b/src/intel/vulkan/Makefile.am index 54a51be..1dee84b 100644 --- a/src/intel/vulkan/Makefile.am +++ b/src/intel/vulkan/Makefile.am @@ -166,7 +166,7 @@ libvulkan_intel_la_LDFLAGS = \ icdconfdir = @VULKAN_ICD_INSTALL_DIR@ -icdconf_DATA = intel_icd.json +icdconf_DATA = intel_icd.@host_cpu@.json # The following is used for development purposes, by setting VK_ICD_FILENAMES. noinst_DATA = dev_icd.json @@ -181,7 +181,7 @@ else ICD_DRIVER_PATH="libvulkan_intel.so" endif -intel_icd.json : <a href="http://intel_icd.json.in" rel="noreferrer" target="_blank">intel_icd.json.in</a> +intel_icd.@host_cpu@.json : <a href="http://intel_icd.json.in" rel="noreferrer" target="_blank">intel_icd.json.in</a> $(AM_V_GEN) $(SED) \ -e "s#@ICD_DRIVER_PATH@#${ICD_DRIVER_PATH}#" \ < $(srcdir)/<a href="http://intel_icd.json.in" rel="noreferrer" target="_blank">intel_icd.json.in</a> > $@ -- 2.5.0.400.gff86faf </blockquote></div> </div></div>