Re: [V2 PATCH 0/6] KVM: selftests: selftests for fd-based private memory

[Kirill A. Shutemov]

On Wed, Jan 18, 2023 at 01:09:49AM +0000, Sean Christopherson wrote:
> On Mon, Dec 05, 2022, Vishal Annapurve wrote:
> > This series implements selftests targeting the feature floated by Chao via:
> > https://lore.kernel.org/lkml/20221202061347.1070246-10-chao.p.peng@xxxxxxxxxxxxxxx/T/
> > 
> > Below changes aim to test the fd based approach for guest private memory
> > in context of normal (non-confidential) VMs executing on non-confidential
> > platforms.
> > 
> > private_mem_test.c file adds selftest to access private memory from the
> > guest via private/shared accesses and checking if the contents can be
> > leaked to/accessed by vmm via shared memory view before/after conversions.
> > 
> > Updates in V2:
> > 1) Simplified vcpu run loop implementation API
> > 2) Removed VM creation logic from private mem library
> 
> I pushed a rework version of this series to:
> 
>   git@xxxxxxxxxx:sean-jc/linux.git x86/upm_base_support

It still has build issue with lockdep enabled that I mentioned before:

https://lore.kernel.org/all/20230116134845.vboraky2nd56szos@xxxxxxxxxxxxxxxxx/

And when compiled with lockdep, it triggers a lot of warnings about missed
locks, like this:

[   59.632024] kvm: FIXME: Walk the memory attributes of the slot and set the mixed status appropriately
[   59.684888] ------------[ cut here ]------------
[   59.690677] WARNING: CPU: 2 PID: 138 at include/linux/kvm_host.h:2307 kvm_mmu_do_page_fault+0x19a/0x1b0
[   59.693531] CPU: 2 PID: 138 Comm: private_mem_con Not tainted 6.1.0-rc4-00624-g7e536bf3c45c-dirty #1
[   59.696265] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
[   59.699586] RIP: 0010:kvm_mmu_do_page_fault+0x19a/0x1b0
[   59.700720] Code: d8 1c 00 00 eb e3 65 48 8b 0c 25 28 00 00 00 48 3b 4c 24 50 75 1b 48 83 c4 58 5b 41 5e 41 5f 5d c3 48 81 c0
[   59.704711] RSP: 0018:ffffc90000323c80 EFLAGS: 00010246
[   59.705830] RAX: 0000000000000000 RBX: ffff888103bc8000 RCX: ffffffff8107dff0
[   59.707353] RDX: 0000000000000001 RSI: ffffffff82549d49 RDI: ffffffff825abe77
[   59.708865] RBP: ffffc90000e59000 R08: 0000000000000000 R09: 0000000000000000
[   59.710369] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[   59.711859] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000180
[   59.713338] FS:  00007f2e556de740(0000) GS:ffff8881f9d00000(0000) knlGS:0000000000000000
[   59.714978] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   59.716168] CR2: 0000000000000000 CR3: 0000000100e90005 CR4: 0000000000372ee0
[   59.717631] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   59.719086] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   59.721148] Call Trace:
[   59.722661]  <TASK>
[   59.723986]  ? lock_is_held_type+0xdb/0x150
[   59.726501]  kvm_mmu_page_fault+0x41/0x170
[   59.728946]  vmx_handle_exit+0x343/0x750
[   59.731007]  kvm_arch_vcpu_ioctl_run+0x1d12/0x2790
[   59.733319]  kvm_vcpu_ioctl+0x4a6/0x590
[   59.735195]  __se_sys_ioctl+0x6a/0xb0
[   59.736976]  do_syscall_64+0x3d/0x80
[   59.738698]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[   59.740743] RIP: 0033:0x7f2e557d8f6b
[   59.741907] Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 c7 04 24 10 00 00 00 b0
[   59.747836] RSP: 002b:00007ffe8b84eb50 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[   59.750147] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f2e557d8f6b
[   59.751754] RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000007
[   59.753361] RBP: 000000000042f880 R08: 0000000000000007 R09: 0000000000430210
[   59.754952] R10: ca7f9f3d969d5d5c R11: 0000000000000246 R12: 000000000042d2a0
[   59.756596] R13: 0000000100000000 R14: 0000000000422e00 R15: 00007f2e558f7000
[   59.758231]  </TASK>
[   59.758752] irq event stamp: 8637
[   59.759540] hardirqs last  enabled at (8647): [<ffffffff8119ae18>] __up_console_sem+0x68/0x90
[   59.761309] hardirqs last disabled at (8654): [<ffffffff8119adfd>] __up_console_sem+0x4d/0x90
[   59.763022] softirqs last  enabled at (8550): [<ffffffff81123c7a>] __irq_exit_rcu+0xaa/0x130
[   59.764731] softirqs last disabled at (8539): [<ffffffff81123c7a>] __irq_exit_rcu+0xaa/0x130
[   59.766409] ---[ end trace 0000000000000000 ]---

-- 
  Kiryl Shutsemau / Kirill A. Shutemov