On Mon, Sep 06, 2021 at 05:26:57PM +0200, Paolo Bonzini wrote: > From: Daniel P. Berrangé <[email protected]> > > Booting Fedora kernels with -cpu max hangs very early in boot. Disabling > the la57 CPUID bit fixes the problem. git bisect traced the regression to > > commit 213ff024a2f92020290296cb9dc29c2af3d4a221 (HEAD, refs/bisect/bad) > Author: Lara Lazier <[email protected]> > Date: Wed Jul 21 17:26:50 2021 +0200 > > target/i386: Added consistency checks for CR4 > > All MBZ bits in CR4 must be zero. (APM2 15.5) > Added reserved bitmask and added checks in both > helper_vmrun and helper_write_crN. > > Signed-off-by: Lara Lazier <[email protected]> > Message-Id: <[email protected]> > Signed-off-by: Paolo Bonzini <[email protected]> > > In this commit CR4_RESERVED_MASK is missing CR4_LA57_MASK and > two others. Adding this lets Fedora kernels boot once again. > > Signed-off-by: Daniel P. Berrangé <[email protected]> > Tested-by: Richard W.M. Jones <[email protected]>
I tested it again and it still works: $ LIBGUESTFS_BACKEND_SETTINGS=force_tcg LIBGUESTFS_HV=$PWD/qemu-system-x86_64 libguestfs-test-tool ... ===== TEST FINISHED OK ===== (versus without the patch where it appears to hang in very early kernel) Rich. > Message-Id: <[email protected]> > [Removed VMXE/SMXE, matching the commit message. - Paolo] > Fixes: 213ff024a2 ("target/i386: Added consistency checks for CR4", > 2021-07-22) > Signed-off-by: Paolo Bonzini <[email protected]> > --- > target/i386/cpu.h | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/target/i386/cpu.h b/target/i386/cpu.h > index 6c50d3ab4f..21b33fbe2e 100644 > --- a/target/i386/cpu.h > +++ b/target/i386/cpu.h > @@ -257,6 +257,7 @@ typedef enum X86Seg { > | CR4_DE_MASK | CR4_PSE_MASK | CR4_PAE_MASK \ > | CR4_MCE_MASK | CR4_PGE_MASK | CR4_PCE_MASK \ > | CR4_OSFXSR_MASK | CR4_OSXMMEXCPT_MASK |CR4_UMIP_MASK \ > + | CR4_LA57_MASK \ > | CR4_FSGSBASE_MASK | CR4_PCIDE_MASK | CR4_OSXSAVE_MASK \ > | CR4_SMEP_MASK | CR4_SMAP_MASK | CR4_PKE_MASK | > CR4_PKS_MASK)) > > -- > 2.31.1 -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-df lists disk usage of guests without needing to install any software inside the virtual machine. Supports Linux and Windows. http://people.redhat.com/~rjones/virt-df/
