On Tue, May 04, 2010 at 05:20:02AM -0400, Avi Kivity wrote: > On 05/04/2010 12:11 PM, Roedel, Joerg wrote: > > On Tue, May 04, 2010 at 03:53:57AM -0400, Avi Kivity wrote: > > > >> On 05/03/2010 07:32 PM, Joerg Roedel wrote: > >> > >>> On Tue, Apr 27, 2010 at 03:58:36PM +0300, Avi Kivity wrote: > >>> > >>> > >>>> So we probably need to upgrade gva_t to a u64. Please send this as > >>>> a separate patch, and test on i386 hosts. > >>>> > >>>> > >>> Are there _any_ regular tests of KVM on i386 hosts? For me this is > >>> terribly broken (also after I fixed the issue which gave me a > >>> VMEXIT_INVALID at the first vmrun). > >>> > >>> > >>> > >> No, apart from the poor users. I'll try to set something up using nsvm. > >> > > Ok. I will post an initial fix for the VMEXIT_INVALID bug soon. Apart > > from that I get a lockdep warning when I try to start a guest. The guest > > actually boots if it is single-vcpu. SMP guests don't even boot through > > the BIOS for me. > > > > > > Strange. i386 vs x86_64 shouldn't have that much effect! This is the lockdep warning I get when I start booting a Linux kernel. It is with the nested-npt patchset but the warning occurs without it too (slightly different backtraces then). [60390.953424] ======================================================= [60390.954324] [ INFO: possible circular locking dependency detected ] [60390.954324] 2.6.34-rc5 #7 [60390.954324] ------------------------------------------------------- [60390.954324] qemu-system-x86/2506 is trying to acquire lock: [60390.954324] (&mm->mmap_sem){++++++}, at: [<c10ab0f4>] might_fault+0x4c/0x86 [60390.954324] [60390.954324] but task is already holding lock: [60390.954324] (&(&kvm->mmu_lock)->rlock){+.+...}, at: [<f8ec1b50>] spin_lock+0xd/0xf [kvm] [60390.954324] [60390.954324] which lock already depends on the new lock. [60390.954324] [60390.954324] [60390.954324] the existing dependency chain (in reverse order) is: [60390.954324] [60390.954324] -> #1 (&(&kvm->mmu_lock)->rlock){+.+...}: [60390.954324] [<c10575ad>] __lock_acquire+0x9fa/0xb6c [60390.954324] [<c10577b8>] lock_acquire+0x99/0xb8 [60390.954324] [<c15afa2b>] _raw_spin_lock+0x20/0x2f [60390.954324] [<f8eafe19>] spin_lock+0xd/0xf [kvm] [60390.954324] [<f8eb104e>] kvm_mmu_notifier_invalidate_range_start+0x2f/0x71 [kvm] [60390.954324] [<c10bc994>] __mmu_notifier_invalidate_range_start+0x31/0x57 [60390.954324] [<c10b1de3>] mprotect_fixup+0x153/0x3d5 [60390.954324] [<c10b21ca>] sys_mprotect+0x165/0x1db [60390.954324] [<c10028cc>] sysenter_do_call+0x12/0x32 [60390.954324] [60390.954324] -> #0 (&mm->mmap_sem){++++++}: [60390.954324] [<c10574af>] __lock_acquire+0x8fc/0xb6c [60390.954324] [<c10577b8>] lock_acquire+0x99/0xb8 [60390.954324] [<c10ab111>] might_fault+0x69/0x86 [60390.954324] [<c11d5987>] _copy_from_user+0x36/0x119 [60390.954324] [<f8eafcd9>] copy_from_user+0xd/0xf [kvm] [60390.954324] [<f8eb0ac0>] kvm_read_guest_page+0x24/0x33 [kvm] [60390.954324] [<f8ebb362>] kvm_read_guest_page_mmu+0x55/0x63 [kvm] [60390.954324] [<f8ebb397>] kvm_read_nested_guest_page+0x27/0x2e [kvm] [60390.954324] [<f8ebb3da>] load_pdptrs+0x3c/0x9e [kvm] [60390.954324] [<f84747ac>] svm_cache_reg+0x25/0x2b [kvm_amd] [60390.954324] [<f8ec7894>] kvm_mmu_load+0xf1/0x1fa [kvm] [60390.954324] [<f8ebbdfc>] kvm_arch_vcpu_ioctl_run+0x252/0x9c7 [kvm] [60390.954324] [<f8eb1fb5>] kvm_vcpu_ioctl+0xee/0x432 [kvm] [60390.954324] [<c10cf8e9>] vfs_ioctl+0x2c/0x96 [60390.954324] [<c10cfe88>] do_vfs_ioctl+0x491/0x4cf [60390.954324] [<c10cff0c>] sys_ioctl+0x46/0x66 [60390.954324] [<c10028cc>] sysenter_do_call+0x12/0x32 [60390.954324] [60390.954324] other info that might help us debug this: [60390.954324] [60390.954324] 3 locks held by qemu-system-x86/2506: [60390.954324] #0: (&vcpu->mutex){+.+.+.}, at: [<f8eb1185>] vcpu_load+0x16/0x32 [kvm] [60390.954324] #1: (&kvm->srcu){.+.+.+}, at: [<f8eb952c>] srcu_read_lock+0x0/0x33 [kvm] [60390.954324] #2: (&(&kvm->mmu_lock)->rlock){+.+...}, at: [<f8ec1b50>] spin_lock+0xd/0xf [kvm] [60390.954324] [60390.954324] stack backtrace: [60390.954324] Pid: 2506, comm: qemu-system-x86 Not tainted 2.6.34-rc5 #7 [60390.954324] Call Trace: [60390.954324] [<c15adf46>] ? printk+0x14/0x16 [60390.954324] [<c1056877>] print_circular_bug+0x8a/0x96 [60390.954324] [<c10574af>] __lock_acquire+0x8fc/0xb6c [60390.954324] [<f8ec1b50>] ? spin_lock+0xd/0xf [kvm] [60390.954324] [<c10ab0f4>] ? might_fault+0x4c/0x86 [60390.954324] [<c10577b8>] lock_acquire+0x99/0xb8 [60390.954324] [<c10ab0f4>] ? might_fault+0x4c/0x86 [60390.954324] [<c10ab111>] might_fault+0x69/0x86 [60390.954324] [<c10ab0f4>] ? might_fault+0x4c/0x86 [60390.954324] [<c11d5987>] _copy_from_user+0x36/0x119 [60390.954324] [<f8eafcd9>] copy_from_user+0xd/0xf [kvm] [60390.954324] [<f8eb0ac0>] kvm_read_guest_page+0x24/0x33 [kvm] [60390.954324] [<f8ebb362>] kvm_read_guest_page_mmu+0x55/0x63 [kvm] [60390.954324] [<f8ebb397>] kvm_read_nested_guest_page+0x27/0x2e [kvm] [60390.954324] [<f8ebb3da>] load_pdptrs+0x3c/0x9e [kvm] [60390.954324] [<f8ec1b50>] ? spin_lock+0xd/0xf [kvm] [60390.954324] [<c15afa32>] ? _raw_spin_lock+0x27/0x2f [60390.954324] [<f84747ac>] svm_cache_reg+0x25/0x2b [kvm_amd] [60390.954324] [<f84747ac>] ? svm_cache_reg+0x25/0x2b [kvm_amd] [60390.954324] [<f8ec7894>] kvm_mmu_load+0xf1/0x1fa [kvm] [60390.954324] [<f8ebbdfc>] kvm_arch_vcpu_ioctl_run+0x252/0x9c7 [kvm] [60390.954324] [<f8eb1fb5>] kvm_vcpu_ioctl+0xee/0x432 [kvm] [60390.954324] [<c1057710>] ? __lock_acquire+0xb5d/0xb6c [60390.954324] [<c107a300>] ? __rcu_process_callbacks+0x6/0x244 [60390.954324] [<c119eb09>] ? file_has_perm+0x84/0x8d [60390.954324] [<c10cf8e9>] vfs_ioctl+0x2c/0x96 [60390.954324] [<f8eb1ec7>] ? kvm_vcpu_ioctl+0x0/0x432 [kvm] [60390.954324] [<c10cfe88>] do_vfs_ioctl+0x491/0x4cf [60390.954324] [<c119ece0>] ? selinux_file_ioctl+0x43/0x46 [60390.954324] [<c10cff0c>] sys_ioctl+0x46/0x66 [60390.954324] [<c10028cc>] sysenter_do_call+0x12/0x32 What makes me wondering about this is that the two traces to the locks seem to belong to different threads. HTH, Joerg -- 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