Bug 2002246
| Summary: | qemu -cpu max + TCG hangs booting Linux because of missing bits in CR4_RESERVED_MASK | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 9 | Reporter: | Richard W.M. Jones <rjones> |
| Component: | qemu-kvm | Assignee: | Daniel Berrangé <berrange> |
| qemu-kvm sub component: | CPU Models | QA Contact: | liunana <nanliu> |
| Status: | CLOSED ERRATA | Docs Contact: | |
| Severity: | unspecified | ||
| Priority: | unspecified | CC: | berrange, coli, jinzhao, juzhang, mrezanin, nanliu, nilal, virt-maint |
| Version: | 9.0 | Keywords: | Triaged |
| Target Milestone: | rc | ||
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | qemu-kvm-6.2.0-1.el9 | Doc Type: | If docs needed, set a value |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2022-05-17 12:24:17 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
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Description
Richard W.M. Jones
2021-09-08 10:46:46 UTC
Assigned to Amnon for initial triage per bz process and age of bug created or assigned to virt-maint without triage. Merged upstream:
commit 69e3895f9d37ca39536775b13ce63e8c291427ba
Author: Daniel P. Berrangé <berrange>
Date: Tue Aug 31 18:50:33 2021 +0100
target/i386: add missing bits to CR4_RESERVED_MASK
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 <laramglazier>
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 <laramglazier>
Message-Id: <20210721152651.14683-2-laramglazier>
Signed-off-by: Paolo Bonzini <pbonzini>
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 <berrange>
Tested-by: Richard W.M. Jones <rjones>
Message-Id: <20210831175033.175584-1-berrange>
[Removed VMXE/SMXE, matching the commit message. - Paolo]
Fixes: 213ff024a2 ("target/i386: Added consistency checks for CR4", 2021-07-22)
Cc: qemu-stable
Signed-off-by: Paolo Bonzini <pbonzini>
Hi Daniel, Would you please tell QE how to test this bug on the QE side? Do we need some tools? Thanks in advance. Best regards Liu Nana Use the following command line: # /usr/libexec/qemu-kvm -kernel /boot/vmlinuz-5.14.0-2.el9.x86_64 -append 'console=ttyS0' -display none -serial stdio -m 1000 -cpu max -accel tcg replacing the vmlinuz path with whatever kernel version you have available on the host. If the CR4 bug is present then this will hang and display no output, while when disabling 'la57' it will work # /usr/libexec/qemu-kvm -kernel /boot/vmlinuz-5.14.0-2.el9.x86_64 -append 'console=ttyS0' -display none -serial stdio -m 1000 -cpu max,-la57 -accel tcg and display kernel boot messages (until it fails to find a rootfs) The fixed QEMU gets rid fo the hang in the first example QE bot(pre verify): Set 'Verified:Tested,SanityOnly' as gating/tier1 test pass. (In reply to Daniel Berrangé from comment #6) > Use the following command line: > > # /usr/libexec/qemu-kvm -kernel /boot/vmlinuz-5.14.0-2.el9.x86_64 -append > 'console=ttyS0' -display none -serial stdio -m 1000 -cpu max -accel tcg > > > replacing the vmlinuz path with whatever kernel version you have available > on the host. > > If the CR4 bug is present then this will hang and display no output, while > when disabling 'la57' it will work > > # /usr/libexec/qemu-kvm -kernel /boot/vmlinuz-5.14.0-2.el9.x86_64 -append > 'console=ttyS0' -display none -serial stdio -m 1000 -cpu max,-la57 -accel tcg > > and display kernel boot messages (until it fails to find a rootfs) > > The fixed QEMU gets rid fo the hang in the first example Thank you, Daniel. I can reproduce this with qemu-kvm-6.1.0-8.el9.x86_64 now. Verify this bug with qemu-img-6.2.0-1.el9.x86_64. Test Env: intel-jacobsville-02.khw2.lab.eng.bos.redhat.com kernel-5.14.0-34.el9.x86_64 qemu-kvm-6.2.0-1.el9.x86_64 Test steps: - Boot qemu with follows command, qemu won't hang and can boot up successfully. # /usr/libexec/qemu-kvm -kernel /boot/vmlinuz-5.14.0-34.el9.x86_64 -append 'console=ttyS0' -display none -serial stdio -m 1000 -cpu max -accel tcg [ 0.000000] Linux version 5.14.0-34.el9.x86_64 (mockbuild.eng.bos.redhat.com) (gcc (GCC) 11.2.1 20211019 (Red Hat 11.2.1-6), GNU ld version 2.35.2-13.el9) #1 SMP PREEMPT Fri Dec 17 23:04:30 EST 2021 [ 0.000000] Command line: console=ttyS0 [ 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 0x008: 'MPX bounds registers' [ 0.000000] x86/fpu: Supporting XSAVE feature 0x010: 'MPX CSR' [ 0.000000] x86/fpu: Supporting XSAVE feature 0x200: 'Protection Keys User registers' [ 0.000000] x86/fpu: xstate_offset[3]: 960, xstate_sizes[3]: 64 [ 0.000000] x86/fpu: xstate_offset[4]: 1024, xstate_sizes[4]: 64 [ 0.000000] x86/fpu: xstate_offset[9]: 2688, xstate_sizes[9]: 8 [ 0.000000] x86/fpu: Enabled xstate features 0x21b, context size is 2696 bytes, using 'standard' format. [ 0.000000] signal: max sigframe size: 3632 [ 0.000000] BIOS-provided physical RAM map: Move this bug to VERIFIED now, thanks. Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (new packages: qemu-kvm), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2022:2307 |