Il 20/08/2014 09:37, Valentine Sinitsyn ha scritto: > Hi Paolo, > > On 20.08.2014 12:55, Paolo Bonzini wrote: >> Is the 0x23c always the same? > No, it's just a garbage - I've seen other values as well (0x80 last time). > >> Can you try this patch? > Sure. It does print a warning: > > [ 2176.722098] ------------[ cut here ]------------ > [ 2176.722118] WARNING: CPU: 0 PID: 1488 at > /home/val/kvm-kmod/x86/x86.c:368 kvm_multiple_exception+0x121/0x130 [kvm]() > [ 2176.722121] Modules linked in: kvm_amd(O) kvm(O) amd_freq_sensitivity > snd_hda_codec_realtek snd_hda_codec_hdmi snd_hda_codec_generic > crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel > snd_hda_intel aesni_intel snd_hda_controller radeon snd_hda_codec > ipmi_si aes_x86_64 ipmi_msghandler snd_hwdep ttm r8169 ppdev mii lrw > gf128mul snd_pcm glue_helper drm_kms_helper snd_timer fam15h_power evdev > drm shpchp snd ablk_helper cryptd microcode mac_hid soundcore serio_raw > pcspkr i2c_algo_bit k10temp i2c_piix4 i2c_core parport_pc parport hwmon > edac_core tpm_tis edac_mce_amd tpm video button acpi_cpufreq processor > ext4 crc16 mbcache jbd2 sd_mod crc_t10dif crct10dif_common atkbd libps2 > ahci libahci ohci_pci ohci_hcd ehci_pci xhci_hcd libata ehci_hcd usbcore > scsi_mod usb_common i8042 serio [last unloaded: kvm] > > [ 2176.722217] CPU: 0 PID: 1488 Comm: qemu-system-x86 Tainted: G W O > 3.16.1-1-ARCH #1 > [ 2176.722221] Hardware name: To Be Filled By O.E.M. To Be Filled By > O.E.M./IMB-A180, BIOS L0.17 05/24/2013 > [ 2176.722224] 0000000000000000 0000000025350f51 ffff8800919fbbc0 > ffffffff8152ae6c > [ 2176.722229] 0000000000000000 ffff8800919fbbf8 ffffffff8106e45d > ffff880037f68000 > [ 2176.722234] 0000000000000080 0000000000000001 00000000000081a4 > 0000000000000000 > [ 2176.722239] Call Trace: > [ 2176.722250] [<ffffffff8152ae6c>] dump_stack+0x4d/0x6f > [ 2176.722257] [<ffffffff8106e45d>] warn_slowpath_common+0x7d/0xa0 > [ 2176.722262] [<ffffffff8106e58a>] warn_slowpath_null+0x1a/0x20 > [ 2176.722275] [<ffffffffa0651e41>] kvm_multiple_exception+0x121/0x130 > [kvm] > [ 2176.722288] [<ffffffffa06594f8>] x86_emulate_instruction+0x548/0x640 > [kvm] > [ 2176.722303] [<ffffffffa06653e1>] kvm_mmu_page_fault+0x91/0xf0 [kvm] > [ 2176.722310] [<ffffffffa04eb6a7>] pf_interception+0xd7/0x180 [kvm_amd] > [ 2176.722317] [<ffffffff8104e876>] ? native_apic_mem_write+0x6/0x10 > [ 2176.722323] [<ffffffffa04ef261>] handle_exit+0x141/0x9d0 [kvm_amd] > [ 2176.722335] [<ffffffffa065512c>] ? kvm_set_cr8+0x1c/0x20 [kvm] > [ 2176.722341] [<ffffffffa04ea3e0>] ? nested_svm_get_tdp_cr3+0x20/0x20 > [kvm_amd] > [ 2176.722355] [<ffffffffa065adc7>] > kvm_arch_vcpu_ioctl_run+0x597/0x1210 [kvm] > [ 2176.722368] [<ffffffffa065705b>] ? kvm_arch_vcpu_load+0xbb/0x200 [kvm] > [ 2176.722378] [<ffffffffa064a152>] kvm_vcpu_ioctl+0x2b2/0x5c0 [kvm] > [ 2176.722384] [<ffffffff810b66b4>] ? __wake_up+0x44/0x50 > [ 2176.722390] [<ffffffff81200dcc>] ? fsnotify+0x28c/0x370 > [ 2176.722397] [<ffffffff811d4a70>] do_vfs_ioctl+0x2d0/0x4b0 > [ 2176.722403] [<ffffffff811df18e>] ? __fget+0x6e/0xb0 > [ 2176.722408] [<ffffffff811d4cd1>] SyS_ioctl+0x81/0xa0 > [ 2176.722414] [<ffffffff81530be9>] system_call_fastpath+0x16/0x1b > [ 2176.722418] ---[ end trace b0f81744c5a5ea4a ]--- > > Thanks, > Valentine > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > I audited the various places that return X86EMUl_PROPAGATE_FAULT and I think the culprit is this code in paging_tmpl.h. real_gpa = mmu->translate_gpa(vcpu, gfn_to_gpa(gfn), access); if (real_gpa == UNMAPPED_GVA) return 0; It returns zero without setting fault.vector. Another patch... I will post parts of it separately, if I am right you should get 0xfe as the vector and a WARN from the gva_to_gpa function. diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index ef297919a691..e5bf13003cd2 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -527,6 +527,7 @@ static unsigned long seg_base(struct x86_emulate_ctxt *ctxt, int seg) static int emulate_exception(struct x86_emulate_ctxt *ctxt, int vec, u32 error, bool valid) { + WARN_ON(vec > 0x1f); ctxt->exception.vector = vec; ctxt->exception.error_code = error; ctxt->exception.error_code_valid = valid; @@ -3016,7 +3015,7 @@ static int em_movbe(struct x86_emulate_ctxt *ctxt) ctxt->dst.val = swab64(ctxt->src.val); break; default: - return X86EMUL_PROPAGATE_FAULT; + BUG(); } return X86EMUL_CONTINUE; } @@ -4829,8 +4828,10 @@ writeback: ctxt->eip = ctxt->_eip; done: - if (rc == X86EMUL_PROPAGATE_FAULT) + if (rc == X86EMUL_PROPAGATE_FAULT) { + WARN_ON(ctxt->exception.vector > 0x1f); ctxt->have_exception = true; + } if (rc == X86EMUL_INTERCEPTED) return EMULATION_INTERCEPTED; diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 410776528265..cd91d03c9320 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -365,8 +365,10 @@ retry_walk: gfn += pse36_gfn_delta(pte); real_gpa = mmu->translate_gpa(vcpu, gfn_to_gpa(gfn), access); - if (real_gpa == UNMAPPED_GVA) + if (real_gpa == UNMAPPED_GVA) { + walker->fault.vector = 0xfe; return 0; + } walker->gfn = real_gpa >> PAGE_SHIFT; @@ -875,8 +877,10 @@ static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr, u32 access, if (r) { gpa = gfn_to_gpa(walker.gfn); gpa |= vaddr & ~PAGE_MASK; - } else if (exception) + } else if (exception) { + WARN_ON(walker.fault.vector > 0x1f); *exception = walker.fault; + } return gpa; } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 737b4bdac41c..71f05585894e 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5248,6 +5249,7 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, ctxt->interruptibility = 0; ctxt->have_exception = false; + ctxt->exception.vector = 0xff; ctxt->perm_ok = false; ctxt->ud = emulation_type & EMULTYPE_TRAP_UD; -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
