** Description changed: + [Impact] + + * QEMU does not work in some AMD hardware when using host-passthrough + as cpu-mode (usually to allow nested KVM to work). + + [Test Case] + + * to use Xenial qemu (1:2.5+dfsg-5ubuntu10.36 ou 1:2.5+dfsg-5ubuntu10.37) + * to use the following XML file: https://paste.ubuntu.com/p/BSyFY7ksR5/ + * to have AMD FX(tm)-8350 Eight-Core Processor CPU or similar + + [Regression Potential] + + * initial qemu code could be affected, disallowing other guests, in other architectures, to be started + * suggested patch is simple, being a positional change only + + [Other Info] + + * INITIAL CASE DESCRIPTION: + When using latest QEMU (-proposed) in Xenial you might encounter the following problem when trying to initialize your guests: ---- (c)inaddy@qemubug:~$ apt-cache policy qemu-system-x86 qemu-system-x86: - Installed: 1:2.5+dfsg-5ubuntu10.37 - Candidate: 1:2.5+dfsg-5ubuntu10.37 - Version table: - *** 1:2.5+dfsg-5ubuntu10.37 500 - 500 http://ubuntu.c3sl.ufpr.br//ubuntu xenial-proposed/main amd64 Packages - 100 /var/lib/dpkg/status - 1:2.5+dfsg-5ubuntu10.36 500 - 500 http://ubuntu.c3sl.ufpr.br//ubuntu xenial-updates/main amd64 Packages - 1:2.5+dfsg-5ubuntu10 500 - 500 http://ubuntu.c3sl.ufpr.br/ubuntu xenial/main amd64 Packages + Installed: 1:2.5+dfsg-5ubuntu10.37 + Candidate: 1:2.5+dfsg-5ubuntu10.37 + Version table: + *** 1:2.5+dfsg-5ubuntu10.37 500 + 500 http://ubuntu.c3sl.ufpr.br//ubuntu xenial-proposed/main amd64 Packages + 100 /var/lib/dpkg/status + 1:2.5+dfsg-5ubuntu10.36 500 + 500 http://ubuntu.c3sl.ufpr.br//ubuntu xenial-updates/main amd64 Packages + 1:2.5+dfsg-5ubuntu10 500 + 500 http://ubuntu.c3sl.ufpr.br/ubuntu xenial/main amd64 Packages ---- (c)inaddy@qemubug:~$ virsh list --all - Id Name State + Id Name State ---------------------------------------------------- - - kdebian shut off - - kguest shut off + - kdebian shut off + - kguest shut off (c)inaddy@qemubug:~$ virsh start --console kguest error: Failed to start domain kguest error: internal error: process exited while connecting to monitor: warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 0] warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 1] warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 2] warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 3] warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 4] warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 5] warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 6] warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 7] warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 8] warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 9] warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 12] warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 13] warning: host doesn't support requested feature: CPU ---- This happens because x86_cpu_get_migratable_flags() does not support CPUID_EXT2_AMD_ALIASES. After cherry-picking upstream patch 9997cf7bdac056aeed246613639675c5a9f8fdc2, that moves CPUID_EXT2_AMD_ALIASES code to after x86_cpu_filter_features(), the problem is fixed. Other QEMU versions are properly fixed and don't face this issue. Cherry-picking commit and re-building the package makes it to work: ---- (c)inaddy@qemubug:~$ virsh start --console kguest Domain kguest started Connected to domain kguest Escape character is ^] [ 0.000000] Linux version 4.19.0-4-amd64 (debian-ker...@lists.debian.org) (gcc version 8.3.0 (Debian 8.3.0-2)) #1 SMP Debian 4.19.28-2 (2019-03-15) [ 0.000000] Command line: root=/dev/vda noresume console=tty0 console=ttyS0,38400n8 apparmor=0 net.ifnames=0 crashkernel=256M [ 0.000000] random: get_random_u32 called from bsp_init_amd+0x20b/0x2b0 with crng_init=0 [ 0.000000] x86/fpu: Supporting XSAVE feature 0x001: 'x87 floating point registers' [ 0.000000] x86/fpu: Supporting XSAVE feature 0x002: 'SSE registers' [ 0.000000] x86/fpu: Supporting XSAVE feature 0x004: 'AVX registers' [ 0.000000] x86/fpu: xstate_offset[2]: 576, xstate_sizes[2]: 256 [ 0.000000] x86/fpu: Enabled xstate features 0x7, context size is 832 bytes, using 'standard' format. ...
** Description changed: [Impact] - * QEMU does not work in some AMD hardware when using host-passthrough + * QEMU does not work in some AMD hardware when using host-passthrough as cpu-mode (usually to allow nested KVM to work). [Test Case] - * to use Xenial qemu (1:2.5+dfsg-5ubuntu10.36 ou 1:2.5+dfsg-5ubuntu10.37) - * to use the following XML file: https://paste.ubuntu.com/p/BSyFY7ksR5/ - * to have AMD FX(tm)-8350 Eight-Core Processor CPU or similar + * to use Xenial qemu (1:2.5+dfsg-5ubuntu10.36 ou 1:2.5+dfsg-5ubuntu10.37) + * to use the following XML file: https://paste.ubuntu.com/p/BSyFY7ksR5/ + * to have AMD FX(tm)-8350 Eight-Core Processor CPU or similar [Regression Potential] - * initial qemu code could be affected, disallowing other guests, in other architectures, to be started - * suggested patch is simple, being a positional change only + * initial qemu code could be affected, disallowing other guests, in other architectures, to be started + * suggested patch is simple, being a positional change only + * patch is upstream based and identifies the issue and is reported to be a fix for the described issue [Other Info] - - * INITIAL CASE DESCRIPTION: + + * INITIAL CASE DESCRIPTION: When using latest QEMU (-proposed) in Xenial you might encounter the following problem when trying to initialize your guests: ---- (c)inaddy@qemubug:~$ apt-cache policy qemu-system-x86 qemu-system-x86: Installed: 1:2.5+dfsg-5ubuntu10.37 Candidate: 1:2.5+dfsg-5ubuntu10.37 Version table: *** 1:2.5+dfsg-5ubuntu10.37 500 500 http://ubuntu.c3sl.ufpr.br//ubuntu xenial-proposed/main amd64 Packages 100 /var/lib/dpkg/status 1:2.5+dfsg-5ubuntu10.36 500 500 http://ubuntu.c3sl.ufpr.br//ubuntu xenial-updates/main amd64 Packages 1:2.5+dfsg-5ubuntu10 500 500 http://ubuntu.c3sl.ufpr.br/ubuntu xenial/main amd64 Packages ---- (c)inaddy@qemubug:~$ virsh list --all Id Name State ---------------------------------------------------- - kdebian shut off - kguest shut off (c)inaddy@qemubug:~$ virsh start --console kguest error: Failed to start domain kguest error: internal error: process exited while connecting to monitor: warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 0] warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 1] warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 2] warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 3] warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 4] warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 5] warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 6] warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 7] warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 8] warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 9] warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 12] warning: host doesn't support requested feature: CPUID.80000001H:EDX [bit 13] warning: host doesn't support requested feature: CPU ---- This happens because x86_cpu_get_migratable_flags() does not support CPUID_EXT2_AMD_ALIASES. After cherry-picking upstream patch 9997cf7bdac056aeed246613639675c5a9f8fdc2, that moves CPUID_EXT2_AMD_ALIASES code to after x86_cpu_filter_features(), the problem is fixed. Other QEMU versions are properly fixed and don't face this issue. Cherry-picking commit and re-building the package makes it to work: ---- (c)inaddy@qemubug:~$ virsh start --console kguest Domain kguest started Connected to domain kguest Escape character is ^] [ 0.000000] Linux version 4.19.0-4-amd64 (debian-ker...@lists.debian.org) (gcc version 8.3.0 (Debian 8.3.0-2)) #1 SMP Debian 4.19.28-2 (2019-03-15) [ 0.000000] Command line: root=/dev/vda noresume console=tty0 console=ttyS0,38400n8 apparmor=0 net.ifnames=0 crashkernel=256M [ 0.000000] random: get_random_u32 called from bsp_init_amd+0x20b/0x2b0 with crng_init=0 [ 0.000000] x86/fpu: Supporting XSAVE feature 0x001: 'x87 floating point registers' [ 0.000000] x86/fpu: Supporting XSAVE feature 0x002: 'SSE registers' [ 0.000000] x86/fpu: Supporting XSAVE feature 0x004: 'AVX registers' [ 0.000000] x86/fpu: xstate_offset[2]: 576, xstate_sizes[2]: 256 [ 0.000000] x86/fpu: Enabled xstate features 0x7, context size is 832 bytes, using 'standard' format. ... -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1828288 Title: QEMU might fail to start on AMD CPUs when 'host-passthrough' is used To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1828288/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
