* Unable to start VM with 5.10-rc3 @ 2020-11-10 15:23 Zdenek Kaspar 2020-11-11 1:13 ` Ben Gardon 0 siblings, 1 reply; 5+ messages in thread From: Zdenek Kaspar @ 2020-11-10 15:23 UTC (permalink / raw) To: kvm@vger.kernel.org [-- Attachment #1: Type: text/plain, Size: 766 bytes --] Hi, attached file is result from today's linux-master (with fixes for 5.10-rc4) when I try to start VM on older machine: model name : Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl cpuid aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm lahf_lm pti tpr_shadow dtherm vmx flags : tsc_offset vtpr I did quick check with 5.9 (distro kernel) and it works, but VM performance seems extremely impacted. 5.8 works fine. Back to 5.10 issue: it's problematic since 5.10-rc1 and I have no luck with bisecting (machine doesn't boot). TIA, Z. [-- Attachment #2: kvm-5.10-rc3-oops --] [-- Type: application/octet-stream, Size: 4791 bytes --] [ 287.307287] BUG: kernel NULL pointer dereference, address: 00000000000000a4 [ 287.307342] #PF: supervisor read access in kernel mode [ 287.307370] #PF: error_code(0x0000) - not-present page [ 287.307398] PGD 0 P4D 0 [ 287.307415] Oops: 0000 [#1] PREEMPT SMP PTI [ 287.307443] CPU: 1 PID: 608 Comm: qemu-build Not tainted 5.10.0-rc3-1-amd64 #1 [ 287.307483] Hardware name: /DG35EC, BIOS ECG3510M.86A.0118.2010.0113.1426 01/13/2010 [ 287.307549] RIP: 0010:is_tdp_mmu_root+0x13/0x30 [kvm] [ 287.307578] Code: 48 8b 87 88 92 00 00 48 81 c7 88 92 00 00 48 39 f8 75 01 c3 0f 0b c3 48 c1 ee 0c 48 c1 e6 06 48 03 35 41 91 29 c9 48 8b 56 28 <0f> b6 82 a4 00 00 00 84 c0 74 08 8b 42 50 85 c0 0f 95 c0 c3 66 0f [ 287.307687] RSP: 0018:ffffb019c06c7c70 EFLAGS: 00010282 [ 287.307717] RAX: ffff9bdeb0a44388 RBX: 0000000000000000 RCX: 0000000000000000 [ 287.307756] RDX: 0000000000000000 RSI: ffffe3bd806b0780 RDI: ffffb019c0985000 [ 287.307795] RBP: 00000000000fe000 R08: 0000000000000002 R09: 0000000000000000 [ 287.307834] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000014 [ 287.307873] R13: ffff9bdeb0a44000 R14: 0000000000000000 R15: 0000000000000001 [ 287.307913] FS: 00007f7f93684640(0000) GS:ffff9bdeff280000(0000) knlGS:0000000000000000 [ 287.307957] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 287.307988] CR2: 00000000000000a4 CR3: 00000000482ee000 CR4: 00000000000026e0 [ 287.308027] Call Trace: [ 287.308055] direct_page_fault+0x66/0x900 [kvm] [ 287.308094] ? writeback_registers+0x18/0x60 [kvm] [ 287.308133] ? x86_emulate_insn+0x5ee/0xe10 [kvm] [ 287.308169] kvm_mmu_page_fault+0x344/0x4f0 [kvm] [ 287.308201] ? vmx_vcpu_enter_exit+0x5c/0x90 [kvm_intel] [ 287.308243] kvm_arch_vcpu_ioctl_run+0xcaa/0x1c60 [kvm] [ 287.308284] kvm_vcpu_ioctl+0x203/0x520 [kvm] [ 287.308313] __x64_sys_ioctl+0x338/0x720 [ 287.308338] ? __x64_sys_futex+0x120/0x190 [ 287.308362] ? restore_altstack+0x14/0xc0 [ 287.308388] do_syscall_64+0x33/0x40 [ 287.308409] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 287.308438] RIP: 0033:0x7f7f94bd1f6b [ 287.308457] Code: 89 d8 49 8d 3c 1c 48 f7 d8 49 39 c4 72 b5 e8 1c ff ff ff 85 c0 78 ba 4c 89 e0 5b 5d 41 5c c3 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d d5 ae 0c 00 f7 d8 64 89 01 48 [ 287.308563] RSP: 002b:00007f7f93683628 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 287.310506] RAX: ffffffffffffffda RBX: 000000000000ae80 RCX: 00007f7f94bd1f6b [ 287.312451] RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000012 [ 287.314336] RBP: 00005570b8032af0 R08: 00005570b60e6850 R09: 00005570b66f9620 [ 287.316212] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 287.318080] R13: 00005570b66db800 R14: 0000000000000000 R15: 00007f7f93684640 [ 287.319927] Modules linked in: vhost_net vhost vhost_iotlb tun nft_reject_ipv4 nf_reject_ipv4 nft_reject nf_tables nfnetlink veth nfsd xxhash_generic nhpoly1305_sse2 nhpoly1305 chacha_generic chacha_x86_64 libchacha adiantum libpoly1305 algif_skcipher af_alg auth_rpcgss nfsv4 dns_resolver nfs lockd grace sunrpc nfs_ssc lzo zram zsmalloc cpufreq_powersave kvm_intel i915 kvm iTCO_wdt lpc_ich bridge video intel_gtt mfd_core 8250 iosf_mbi 8250_base irqbypass i2c_algo_bit evdev e1000e stp llc drm_kms_helper serial_core acpi_cpufreq processor syscopyarea sysfillrect sysimgblt fb_sys_fops button drm sch_fq_codel i2c_core backlight ip_tables x_tables ipv6 autofs4 btrfs blake2b_generic libcrc32c crc32c_generic xor zstd_decompress zstd_compress lzo_compress lzo_decompress raid6_pq ecb xts dm_crypt dm_mod sd_mod t10_pi hid_generic usbhid hid uhci_hcd ehci_pci ehci_hcd ahci sata_sil24 pata_jmicron libahci usbcore usb_common [ 287.332454] CR2: 00000000000000a4 [ 287.334683] ---[ end trace abb75000bdcae706 ]--- [ 287.336922] RIP: 0010:is_tdp_mmu_root+0x13/0x30 [kvm] [ 287.339211] Code: 48 8b 87 88 92 00 00 48 81 c7 88 92 00 00 48 39 f8 75 01 c3 0f 0b c3 48 c1 ee 0c 48 c1 e6 06 48 03 35 41 91 29 c9 48 8b 56 28 <0f> b6 82 a4 00 00 00 84 c0 74 08 8b 42 50 85 c0 0f 95 c0 c3 66 0f [ 287.343891] RSP: 0018:ffffb019c06c7c70 EFLAGS: 00010282 [ 287.346272] RAX: ffff9bdeb0a44388 RBX: 0000000000000000 RCX: 0000000000000000 [ 287.348665] RDX: 0000000000000000 RSI: ffffe3bd806b0780 RDI: ffffb019c0985000 [ 287.351085] RBP: 00000000000fe000 R08: 0000000000000002 R09: 0000000000000000 [ 287.353499] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000014 [ 287.355912] R13: ffff9bdeb0a44000 R14: 0000000000000000 R15: 0000000000000001 [ 287.358336] FS: 00007f7f93684640(0000) GS:ffff9bdeff280000(0000) knlGS:0000000000000000 [ 287.360768] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 287.363207] CR2: 00000000000000a4 CR3: 00000000482ee000 CR4: 00000000000026e0 ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Unable to start VM with 5.10-rc3 2020-11-10 15:23 Unable to start VM with 5.10-rc3 Zdenek Kaspar @ 2020-11-11 1:13 ` Ben Gardon 2020-11-11 11:09 ` Zdenek Kaspar 0 siblings, 1 reply; 5+ messages in thread From: Ben Gardon @ 2020-11-11 1:13 UTC (permalink / raw) To: Zdenek Kaspar; +Cc: kvm@vger.kernel.org, Jim Mattson Hi Zdenek, That crash is most likely the result of a missing check for an invalid root HPA or NULL shadow page in is_tdp_mmu_root, which could have prevented the NULL pointer dereference. However, I'm not sure how a vCPU got to that point in the page fault handler with a bad EPT root page. I see VMX in your list of flags, is your machine 64 bit with EPT or some other configuration? I'm surprised you are finding your machine unable to boot for bisecting. Do you know if it's crashing in the same spot or somewhere else? I wouldn't expect the KVM page fault handler to run as part of boot. I will send out a patch first thing tomorrow morning (PST) to WARN instead of crashing with a NULL pointer dereference. Are you able to reproduce the issue with any KVM selftest? Ben On Tue, Nov 10, 2020 at 7:24 AM Zdenek Kaspar <zkaspar82@gmail.com> wrote: > > Hi, > > attached file is result from today's linux-master (with fixes > for 5.10-rc4) when I try to start VM on older machine: > > model name : Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz > flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl cpuid aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm lahf_lm pti tpr_shadow dtherm > vmx flags : tsc_offset vtpr > > I did quick check with 5.9 (distro kernel) and it works, > but VM performance seems extremely impacted. 5.8 works fine. > > Back to 5.10 issue: it's problematic since 5.10-rc1 and I have no luck > with bisecting (machine doesn't boot). > > TIA, Z. ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Unable to start VM with 5.10-rc3 2020-11-11 1:13 ` Ben Gardon @ 2020-11-11 11:09 ` Zdenek Kaspar 2020-11-11 18:37 ` Ben Gardon 0 siblings, 1 reply; 5+ messages in thread From: Zdenek Kaspar @ 2020-11-11 11:09 UTC (permalink / raw) To: Ben Gardon; +Cc: kvm@vger.kernel.org, Jim Mattson [-- Attachment #1: Type: text/plain, Size: 2176 bytes --] Hi, I'm sure my bisect has nothing to do with KVM, because it was quick shot between -rc1 and previous release. This old CPU doesn't have EPT (see attached file) ./run_tests.sh FAIL apic-split (timeout; duration=90s) FAIL ioapic-split (timeout; duration=90s) FAIL apic (timeout; duration=30) ... ^C few RIP is_tdp_mmu_root observed in dmesg Z. On Tue, 10 Nov 2020 17:13:21 -0800 Ben Gardon <bgardon@google.com> wrote: > Hi Zdenek, > > That crash is most likely the result of a missing check for an invalid > root HPA or NULL shadow page in is_tdp_mmu_root, which could have > prevented the NULL pointer dereference. > However, I'm not sure how a vCPU got to that point in the page fault > handler with a bad EPT root page. > > I see VMX in your list of flags, is your machine 64 bit with EPT or > some other configuration? > > I'm surprised you are finding your machine unable to boot for > bisecting. Do you know if it's crashing in the same spot or somewhere > else? I wouldn't expect the KVM page fault handler to run as part of > boot. > > I will send out a patch first thing tomorrow morning (PST) to WARN > instead of crashing with a NULL pointer dereference. Are you able to > reproduce the issue with any KVM selftest? > > Ben > > > On Tue, Nov 10, 2020 at 7:24 AM Zdenek Kaspar <zkaspar82@gmail.com> > wrote: > > > > Hi, > > > > attached file is result from today's linux-master (with fixes > > for 5.10-rc4) when I try to start VM on older machine: > > > > model name : Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz > > flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr > > pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ht tm pbe > > syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl > > cpuid aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 > > xtpr pdcm lahf_lm pti tpr_shadow dtherm vmx flags : > > tsc_offset vtpr > > > > I did quick check with 5.9 (distro kernel) and it works, > > but VM performance seems extremely impacted. 5.8 works fine. > > > > Back to 5.10 issue: it's problematic since 5.10-rc1 and I have no > > luck with bisecting (machine doesn't boot). > > > > TIA, Z. [-- Attachment #2: vmxcap-out --] [-- Type: application/octet-stream, Size: 5466 bytes --] Basic VMX Information Hex: 0x1a040000000007 Revision 7 VMCS size 1024 VMCS restricted to 32 bit addresses no Dual-monitor support yes VMCS memory type 6 INS/OUTS instruction information no IA32_VMX_TRUE_*_CTLS support no pin-based controls External interrupt exiting yes NMI exiting yes Virtual NMIs no Activate VMX-preemption timer no Process posted interrupts no primary processor-based controls Interrupt window exiting yes Use TSC offsetting yes HLT exiting yes INVLPG exiting yes MWAIT exiting yes RDPMC exiting yes RDTSC exiting yes CR3-load exiting forced CR3-store exiting forced CR8-load exiting yes CR8-store exiting yes Use TPR shadow yes NMI-window exiting no MOV-DR exiting yes Unconditional I/O exiting yes Use I/O bitmaps yes Monitor trap flag no Use MSR bitmaps yes MONITOR exiting yes PAUSE exiting yes Activate secondary control no secondary processor-based controls Virtualize APIC accesses no Enable EPT no Descriptor-table exiting no Enable RDTSCP no Virtualize x2APIC mode no Enable VPID no WBINVD exiting no Unrestricted guest no APIC register emulation no Virtual interrupt delivery no PAUSE-loop exiting no RDRAND exiting no Enable INVPCID no Enable VM functions no VMCS shadowing no Enable ENCLS exiting no RDSEED exiting no Enable PML no EPT-violation #VE no Conceal non-root operation from PT no Enable XSAVES/XRSTORS no Mode-based execute control (XS/XU) no Sub-page write permissions no GPA translation for PT no TSC scaling no User wait and pause no ENCLV exiting no VM-Exit controls Save debug controls forced Host address-space size yes Load IA32_PERF_GLOBAL_CTRL no Acknowledge interrupt on exit yes Save IA32_PAT no Load IA32_PAT no Save IA32_EFER no Load IA32_EFER no Save VMX-preemption timer value no Clear IA32_BNDCFGS no Conceal VM exits from PT no Clear IA32_RTIT_CTL no VM-Entry controls Load debug controls forced IA-32e mode guest yes Entry to SMM yes Deactivate dual-monitor treatment yes Load IA32_PERF_GLOBAL_CTRL no Load IA32_PAT no Load IA32_EFER no Load IA32_BNDCFGS no Conceal VM entries from PT no Load IA32_RTIT_CTL no Miscellaneous data Hex: 0x403c0 VMX-preemption timer scale (log2) 0 Store EFER.LMA into IA-32e mode guest control no HLT activity state yes Shutdown activity state yes Wait-for-SIPI activity state yes PT in VMX operation no IA32_SMBASE support no Number of CR3-target values 4 MSR-load/store count recommendation 0 IA32_SMM_MONITOR_CTL[2] can be set to 1 no VMWRITE to VM-exit information fields no Inject event with insn length=0 no MSEG revision identifier 0 VPID and EPT capabilities Hex: 0x0 Execute-only EPT translations no Page-walk length 4 no Paging-structure memory type UC no Paging-structure memory type WB no 2MB EPT pages no 1GB EPT pages no INVEPT supported no EPT accessed and dirty flags no Advanced VM-exit information for EPT violations no Single-context INVEPT no All-context INVEPT no INVVPID supported no Individual-address INVVPID no Single-context INVVPID no All-context INVVPID no Single-context-retaining-globals INVVPID no VM Functions Hex: 0x0 EPTP Switching no ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Unable to start VM with 5.10-rc3 2020-11-11 11:09 ` Zdenek Kaspar @ 2020-11-11 18:37 ` Ben Gardon 2020-11-11 22:16 ` Zdenek Kaspar 0 siblings, 1 reply; 5+ messages in thread From: Ben Gardon @ 2020-11-11 18:37 UTC (permalink / raw) To: Zdenek Kaspar; +Cc: kvm@vger.kernel.org, Jim Mattson Hi Zdenek, I'm working on reproducing the issue. I don't have access to a CPU without EPT, but I tried turning off EPT on a Skylake and I think I reproduced the issue, but wasn't able to confirm in the logs. If you were operating without EPT I assume the guest was in non-paging mode to get into direct_page_fault in the first place. I would still have expected the root HPA to be valid unless... Ah, if you're operating with PAE, then the root hpa will be valid but not have a shadow page associated with it, as it is set to __pa(vcpu->arch.mmu->pae_root) in mmu_alloc_direct_roots. In that case, I can see why we get a NULL pointer dereference in is_tdp_mmu_root. I will send out a patch that should fix this if the issue is as described above. I don't have hardware to test this on, but if you don't mind applying the patch and checking it, that would be awesome. Ben On Wed, Nov 11, 2020 at 3:09 AM Zdenek Kaspar <zkaspar82@gmail.com> wrote: > > Hi, I'm sure my bisect has nothing to do with KVM, > because it was quick shot between -rc1 and previous release. > > This old CPU doesn't have EPT (see attached file) > > ./run_tests.sh > FAIL apic-split (timeout; duration=90s) > FAIL ioapic-split (timeout; duration=90s) > FAIL apic (timeout; duration=30) > ... ^C > few RIP is_tdp_mmu_root observed in dmesg > > Z. > > On Tue, 10 Nov 2020 17:13:21 -0800 > Ben Gardon <bgardon@google.com> wrote: > > > Hi Zdenek, > > > > That crash is most likely the result of a missing check for an invalid > > root HPA or NULL shadow page in is_tdp_mmu_root, which could have > > prevented the NULL pointer dereference. > > However, I'm not sure how a vCPU got to that point in the page fault > > handler with a bad EPT root page. > > > > I see VMX in your list of flags, is your machine 64 bit with EPT or > > some other configuration? > > > > I'm surprised you are finding your machine unable to boot for > > bisecting. Do you know if it's crashing in the same spot or somewhere > > else? I wouldn't expect the KVM page fault handler to run as part of > > boot. > > > > I will send out a patch first thing tomorrow morning (PST) to WARN > > instead of crashing with a NULL pointer dereference. Are you able to > > reproduce the issue with any KVM selftest? > > > > Ben > > > > > > On Tue, Nov 10, 2020 at 7:24 AM Zdenek Kaspar <zkaspar82@gmail.com> > > wrote: > > > > > > Hi, > > > > > > attached file is result from today's linux-master (with fixes > > > for 5.10-rc4) when I try to start VM on older machine: > > > > > > model name : Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz > > > flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr > > > pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ht tm pbe > > > syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl > > > cpuid aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 > > > xtpr pdcm lahf_lm pti tpr_shadow dtherm vmx flags : > > > tsc_offset vtpr > > > > > > I did quick check with 5.9 (distro kernel) and it works, > > > but VM performance seems extremely impacted. 5.8 works fine. > > > > > > Back to 5.10 issue: it's problematic since 5.10-rc1 and I have no > > > luck with bisecting (machine doesn't boot). > > > > > > TIA, Z. > ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Unable to start VM with 5.10-rc3 2020-11-11 18:37 ` Ben Gardon @ 2020-11-11 22:16 ` Zdenek Kaspar 0 siblings, 0 replies; 5+ messages in thread From: Zdenek Kaspar @ 2020-11-11 22:16 UTC (permalink / raw) To: Ben Gardon; +Cc: kvm@vger.kernel.org, Jim Mattson Hi Ben, [PATCH] kvm: x86/mmu: Fix is_tdp_mmu_check when using PAE fixes is_tdp_mmu_root NULL pointer dereference, tested on: Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz Thanks, Z. On Wed, 11 Nov 2020 10:37:49 -0800 Ben Gardon <bgardon@google.com> wrote: > Hi Zdenek, > > I'm working on reproducing the issue. I don't have access to a CPU > without EPT, but I tried turning off EPT on a Skylake and I think I > reproduced the issue, but wasn't able to confirm in the logs. > > If you were operating without EPT I assume the guest was in non-paging > mode to get into direct_page_fault in the first place. I would still > have expected the root HPA to be valid unless... > > Ah, if you're operating with PAE, then the root hpa will be valid but > not have a shadow page associated with it, as it is set to > __pa(vcpu->arch.mmu->pae_root) in mmu_alloc_direct_roots. > In that case, I can see why we get a NULL pointer dereference in > is_tdp_mmu_root. > > I will send out a patch that should fix this if the issue is as > described above. I don't have hardware to test this on, but if you > don't mind applying the patch and checking it, that would be awesome. > > Ben > > On Wed, Nov 11, 2020 at 3:09 AM Zdenek Kaspar <zkaspar82@gmail.com> > wrote: > > > > Hi, I'm sure my bisect has nothing to do with KVM, > > because it was quick shot between -rc1 and previous release. > > > > This old CPU doesn't have EPT (see attached file) > > > > ./run_tests.sh > > FAIL apic-split (timeout; duration=90s) > > FAIL ioapic-split (timeout; duration=90s) > > FAIL apic (timeout; duration=30) > > ... ^C > > few RIP is_tdp_mmu_root observed in dmesg > > > > Z. > > > > On Tue, 10 Nov 2020 17:13:21 -0800 > > Ben Gardon <bgardon@google.com> wrote: > > > > > Hi Zdenek, > > > > > > That crash is most likely the result of a missing check for an > > > invalid root HPA or NULL shadow page in is_tdp_mmu_root, which > > > could have prevented the NULL pointer dereference. > > > However, I'm not sure how a vCPU got to that point in the page > > > fault handler with a bad EPT root page. > > > > > > I see VMX in your list of flags, is your machine 64 bit with EPT > > > or some other configuration? > > > > > > I'm surprised you are finding your machine unable to boot for > > > bisecting. Do you know if it's crashing in the same spot or > > > somewhere else? I wouldn't expect the KVM page fault handler to > > > run as part of boot. > > > > > > I will send out a patch first thing tomorrow morning (PST) to WARN > > > instead of crashing with a NULL pointer dereference. Are you able > > > to reproduce the issue with any KVM selftest? > > > > > > Ben > > > > > > > > > On Tue, Nov 10, 2020 at 7:24 AM Zdenek Kaspar > > > <zkaspar82@gmail.com> wrote: > > > > > > > > Hi, > > > > > > > > attached file is result from today's linux-master (with fixes > > > > for 5.10-rc4) when I try to start VM on older machine: > > > > > > > > model name : Intel(R) Core(TM)2 CPU 6600 @ > > > > 2.40GHz flags : fpu vme de pse tsc msr pae mce cx8 > > > > apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr > > > > sse sse2 ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs > > > > bts rep_good nopl cpuid aperfmperf pni dtes64 monitor ds_cpl > > > > vmx est tm2 ssse3 cx16 xtpr pdcm lahf_lm pti tpr_shadow dtherm > > > > vmx flags : tsc_offset vtpr > > > > > > > > I did quick check with 5.9 (distro kernel) and it works, > > > > but VM performance seems extremely impacted. 5.8 works fine. > > > > > > > > Back to 5.10 issue: it's problematic since 5.10-rc1 and I have > > > > no luck with bisecting (machine doesn't boot). > > > > > > > > TIA, Z. > > ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2020-11-11 22:16 UTC | newest] Thread overview: 5+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2020-11-10 15:23 Unable to start VM with 5.10-rc3 Zdenek Kaspar 2020-11-11 1:13 ` Ben Gardon 2020-11-11 11:09 ` Zdenek Kaspar 2020-11-11 18:37 ` Ben Gardon 2020-11-11 22:16 ` Zdenek Kaspar
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