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Borislav Petkov
a80c4ec10e
After commit:672ff6cff8("KVM: x86: Raise #GP when guest vCPU do not support PMU") my AMD guests started #GPing like this: general protection fault: 0000 [#1] PREEMPT SMP CPU: 1 PID: 4355 Comm: bash Not tainted 5.1.0-rc6+ #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:x86_perf_event_update+0x3b/0xa0 with Code: pointing to RDPMC. It is RDPMC because the guest has the hardware watchdog CONFIG_HARDLOCKUP_DETECTOR_PERF enabled which uses perf. Instrumenting kvm_pmu_rdpmc() some, showed that it fails due to: if (!pmu->version) return 1; which the above commit added. Since AMD's PMU leaves the version at 0, that causes the #GP injection into the guest. Set pmu->version arbitrarily to 1 and move it above the non-applicable struct kvm_pmu members. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com> Cc: kvm@vger.kernel.org Cc: Liran Alon <liran.alon@oracle.com> Cc: Mihai Carabas <mihai.carabas@oracle.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: x86@kernel.org Cc: stable@vger.kernel.org Fixes:672ff6cff8("KVM: x86: Raise #GP when guest vCPU do not support PMU") Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.