diff options
author | Martin Schwaighofer <mschwaig@users.noreply.github.com> | 2021-11-05 19:13:47 +0100 |
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committer | Alyssa Ross <hi@alyssa.is> | 2021-11-30 13:06:22 +0000 |
commit | 08bbd123d562fb13d031cdd955dbe21097a6e9c0 (patch) | |
tree | 4fb17900953f164849e6d2cf6d9e95449c54b961 /pkgs/applications/virtualization | |
parent | 5d06f6933d5373f9f4c4ea63d03029869855f876 (diff) |
qemu: emit warnings when KVM acceleration is not usable
This fixes the qemu-kvm wrapper we add for convenience silently not using KVM, when the system would support it by at least leaving an indication in the log that the build ran slower because it ran without KVM.
Diffstat (limited to 'pkgs/applications/virtualization')
-rw-r--r-- | pkgs/applications/virtualization/qemu/default.nix | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/pkgs/applications/virtualization/qemu/default.nix b/pkgs/applications/virtualization/qemu/default.nix index 7e89871786d65..b4a31c657cdcd 100644 --- a/pkgs/applications/virtualization/qemu/default.nix +++ b/pkgs/applications/virtualization/qemu/default.nix @@ -1,7 +1,7 @@ { lib, stdenv, fetchurl, fetchpatch, python, zlib, pkg-config, glib , perl, pixman, vde2, alsa-lib, texinfo, flex , bison, lzo, snappy, libaio, libtasn1, gnutls, nettle, curl, ninja, meson, sigtool -, makeWrapper, autoPatchelfHook +, makeWrapper, autoPatchelfHook, runtimeShell , attr, libcap, libcap_ng , CoreServices, Cocoa, Hypervisor, rez, setfile , numaSupport ? stdenv.isLinux && !stdenv.isAarch32, numactl @@ -228,9 +228,12 @@ stdenv.mkDerivation rec { # Add a ‘qemu-kvm’ wrapper for compatibility/convenience. postInstall = '' + cp -- $emitKvmWarningsPath $out/libexec/emit-kvm-warnings + chmod a+x -- $out/libexec/emit-kvm-warnings if [ -x $out/bin/qemu-system-${stdenv.hostPlatform.qemuArch} ]; then makeWrapper $out/bin/qemu-system-${stdenv.hostPlatform.qemuArch} \ $out/bin/qemu-kvm \ + --run $out/libexec/emit-kvm-warnings \ --add-flags "\$([ -r /dev/kvm -a -w /dev/kvm ] && echo -enable-kvm)" fi ''; @@ -242,6 +245,26 @@ stdenv.mkDerivation rec { # Builds in ~3h with 2 cores, and ~20m with a big-parallel builder. requiredSystemFeatures = [ "big-parallel" ]; + emitKvmWarnings = '' + #!${runtimeShell} + WARNCOL='\033[1;35m' + NEUTRALCOL='\033[0m' + WARNING="''${WARNCOL}warning:''${NEUTRALCOL}" + if [ ! -e /dev/kvm ]; then + echo -e "''${WARNING} KVM is not available - execution will be slow" >&2 + echo "Consider installing KVM for hardware-accelerated execution." >&2 + echo "If KVM is already installed make sure the kernel module is loaded." >&2 + elif [ ! -r /dev/kvm -o ! -w /dev/kvm ]; then + echo -e "''${WARNING} /dev/kvm is not read-/writable - execution will be slow" >&2 + echo "/dev/kvm needs to be read-/writable by the user executing QEMU." >&2 + echo "" >&2 + echo "For hardware-acceleration inside the nix build sandbox /dev/kvm" >&2 + echo "must be world-read-/writable (rw-rw-rw-)." >&2 + fi + ''; + + passAsFile = [ "emitKvmWarnings" ]; + meta = with lib; { homepage = "http://www.qemu.org/"; description = "A generic and open source machine emulator and virtualizer"; |