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Question: what's the state and next step for this new feature? #5

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aledbf opened this issue Mar 27, 2024 · 8 comments
Closed

Question: what's the state and next step for this new feature? #5

aledbf opened this issue Mar 27, 2024 · 8 comments

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@aledbf
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aledbf commented Mar 27, 2024

Thank you for adding this new feature.
I was wondering if there's a way to track the status of it. I haven't seen any updates in the mailing list thread.
Thanks!

@laijs
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laijs commented Apr 1, 2024

@aledbf I'm glad that you are interested in it. Thank you too.

We have been fixing some problems (from this github issues, private emails, and internal reviews/testings).

We are going to push the effort to make the Linux kernel PIE and fix the problem of the x86 entry code which PVM is highly dependent on. We may send the V2 patchset along the way.

@aledbf aledbf closed this as completed Apr 1, 2024
@aledbf
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aledbf commented Apr 3, 2024

@laijs just one question, it seems I'm missing something to get more than one core? Testing on an Amazon EC2 c6i.8xlarge with --cpus boot=8

cat /proc/cpuinfo 
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 106
model name      : Intel(R) Xeon(R) Platinum 8375C CPU @ 2.90GHz
stepping        : 6
microcode       : 0x1
cpu MHz         : 2899.952
cache size      : 55296 KB
physical id     : 0
siblings        : 1
core id         : 0
cpu cores       : 1
apicid          : 0
initial apicid  : 0
fpu             : yes
fpu_exception   : yes
cpuid level     : 27
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx pdpe1gb rdtscp lm constant_tsc rep_good nopl nonstop_tsc cpuid tsc_known_freq pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch pti ssbd ibpb stibp ibrs_enhanced kvm_pvm_guest fsgsbase tsc_adjust bmi1 avx2 bmi2 erms invpcid avx512f avx512dq rdseed adx avx512ifma clflushopt clwb avx512cd sha_ni avx512bw avx512vl xsaveopt xsavec xgetbv1 wbnoinvd arat avx512vbmi avx512_vbmi2 gfni vaes vpclmulqdq avx512_vnni avx512_bitalg avx512_vpopcntdq rdpid md_clear flush_l1d arch_capabilities
bugs            : spectre_v1 spectre_v2 spec_store_bypass swapgs mmio_stale_data eibrs_pbrsb gds
bogomips        : 5799.90
clflush size    : 64
cache_alignment : 64
address sizes   : 46 bits physical, 48 bits virtual
power management:

@aledbf
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aledbf commented Apr 3, 2024

Testing firecracker I see the right number of cores.

@laijs
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laijs commented Apr 10, 2024

@aledbf Thank you for the test.

Has the problem been fixed? what was the VMM?

@aledbf
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aledbf commented Apr 10, 2024

@laijs firecracker works as expected, except for restoring a snapshot. Besides this detail, it just works.

I have one question: what's the performance "penalty" for using PVM?
Thanks!

@laijs
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laijs commented Apr 10, 2024

@aledbf

The most significant drawback of PVM is shadowpaging. Shadowpaging
results in very bad performance when guest applications frequently
modify pagetable, including excessive processes forking.

@bysui
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bysui commented Apr 10, 2024

@laijs firecracker works as expected, except for restoring a snapshot. Besides this detail, it just works.

I have one question: what's the performance "penalty" for using PVM? Thanks!

Hi @aledbf, is this related to the problem mentioned in #2 (comment) ?
Firecracker doesn't save/restore PVM MSRs.

@aledbf
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aledbf commented Apr 10, 2024

@bysui yes, exactly that. Thanks. I will test firecracker with the change 🙏

pojntfx pushed a commit to loopholelabs/linux-pvm that referenced this issue Oct 18, 2024
Validate next header's offset in ->next_header() so that it isn't
smaller than MID_HEADER_SIZE(server) and then standard_receive3() or
->receive() ends up writing off the end of the buffer because
'pdu_length - MID_HEADER_SIZE(server)' wraps up to a huge length:

  BUG: KASAN: slab-out-of-bounds in _copy_to_iter+0x4fc/0x840
  Write of size 701 at addr ffff88800caf407f by task cifsd/1090

  CPU: 0 PID: 1090 Comm: cifsd Not tainted 6.7.0-rc4 virt-pvm#5
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
  rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
  Call Trace:
   <TASK>
   dump_stack_lvl+0x4a/0x80
   print_report+0xcf/0x650
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __phys_addr+0x46/0x90
   kasan_report+0xd8/0x110
   ? _copy_to_iter+0x4fc/0x840
   ? _copy_to_iter+0x4fc/0x840
   kasan_check_range+0x105/0x1b0
   __asan_memcpy+0x3c/0x60
   _copy_to_iter+0x4fc/0x840
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? hlock_class+0x32/0xc0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __pfx__copy_to_iter+0x10/0x10
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? lock_is_held_type+0x90/0x100
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __might_resched+0x278/0x360
   ? __pfx___might_resched+0x10/0x10
   ? srso_alias_return_thunk+0x5/0xfbef5
   __skb_datagram_iter+0x2c2/0x460
   ? __pfx_simple_copy_to_iter+0x10/0x10
   skb_copy_datagram_iter+0x6c/0x110
   tcp_recvmsg_locked+0x9be/0xf40
   ? __pfx_tcp_recvmsg_locked+0x10/0x10
   ? mark_held_locks+0x5d/0x90
   ? srso_alias_return_thunk+0x5/0xfbef5
   tcp_recvmsg+0xe2/0x310
   ? __pfx_tcp_recvmsg+0x10/0x10
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? lock_acquire+0x14a/0x3a0
   ? srso_alias_return_thunk+0x5/0xfbef5
   inet_recvmsg+0xd0/0x370
   ? __pfx_inet_recvmsg+0x10/0x10
   ? __pfx_lock_release+0x10/0x10
   ? do_raw_spin_trylock+0xd1/0x120
   sock_recvmsg+0x10d/0x150
   cifs_readv_from_socket+0x25a/0x490 [cifs]
   ? __pfx_cifs_readv_from_socket+0x10/0x10 [cifs]
   ? srso_alias_return_thunk+0x5/0xfbef5
   cifs_read_from_socket+0xb5/0x100 [cifs]
   ? __pfx_cifs_read_from_socket+0x10/0x10 [cifs]
   ? __pfx_lock_release+0x10/0x10
   ? do_raw_spin_trylock+0xd1/0x120
   ? _raw_spin_unlock+0x23/0x40
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __smb2_find_mid+0x126/0x230 [cifs]
   cifs_demultiplex_thread+0xd39/0x1270 [cifs]
   ? __pfx_cifs_demultiplex_thread+0x10/0x10 [cifs]
   ? __pfx_lock_release+0x10/0x10
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? mark_held_locks+0x1a/0x90
   ? lockdep_hardirqs_on_prepare+0x136/0x210
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __kthread_parkme+0xce/0xf0
   ? __pfx_cifs_demultiplex_thread+0x10/0x10 [cifs]
   kthread+0x18d/0x1d0
   ? kthread+0xdb/0x1d0
   ? __pfx_kthread+0x10/0x10
   ret_from_fork+0x34/0x60
   ? __pfx_kthread+0x10/0x10
   ret_from_fork_asm+0x1b/0x30
   </TASK>

Fixes: 8ce79ec ("cifs: update multiplex loop to handle compounded responses")
Cc: [email protected]
Reported-by: Robert Morris <[email protected]>
Signed-off-by: Paulo Alcantara (SUSE) <[email protected]>
Signed-off-by: Steve French <[email protected]>
pojntfx pushed a commit to loopholelabs/linux-pvm that referenced this issue Oct 18, 2024
A small CIFS buffer (448 bytes) isn't big enough to hold
SMB2_QUERY_INFO request along with user's input data from
CIFS_QUERY_INFO ioctl.  That is, if the user passed an input buffer >
344 bytes, the client will memcpy() off the end of @req->Buffer in
SMB2_query_info_init() thus causing the following KASAN splat:

  BUG: KASAN: slab-out-of-bounds in SMB2_query_info_init+0x242/0x250 [cifs]
  Write of size 1023 at addr ffff88801308c5a8 by task a.out/1240

  CPU: 1 PID: 1240 Comm: a.out Not tainted 6.7.0-rc4 virt-pvm#5
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
  rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
  Call Trace:
   <TASK>
   dump_stack_lvl+0x4a/0x80
   print_report+0xcf/0x650
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __phys_addr+0x46/0x90
   kasan_report+0xd8/0x110
   ? SMB2_query_info_init+0x242/0x250 [cifs]
   ? SMB2_query_info_init+0x242/0x250 [cifs]
   kasan_check_range+0x105/0x1b0
   __asan_memcpy+0x3c/0x60
   SMB2_query_info_init+0x242/0x250 [cifs]
   ? __pfx_SMB2_query_info_init+0x10/0x10 [cifs]
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? smb_rqst_len+0xa6/0xc0 [cifs]
   smb2_ioctl_query_info+0x4f4/0x9a0 [cifs]
   ? __pfx_smb2_ioctl_query_info+0x10/0x10 [cifs]
   ? __pfx_cifsConvertToUTF16+0x10/0x10 [cifs]
   ? kasan_set_track+0x25/0x30
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __kasan_kmalloc+0x8f/0xa0
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? cifs_strndup_to_utf16+0x12d/0x1a0 [cifs]
   ? __build_path_from_dentry_optional_prefix+0x19d/0x2d0 [cifs]
   ? __pfx_smb2_ioctl_query_info+0x10/0x10 [cifs]
   cifs_ioctl+0x11c7/0x1de0 [cifs]
   ? __pfx_cifs_ioctl+0x10/0x10 [cifs]
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? rcu_is_watching+0x23/0x50
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? __rseq_handle_notify_resume+0x6cd/0x850
   ? __pfx___schedule+0x10/0x10
   ? blkcg_iostat_update+0x250/0x290
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? ksys_write+0xe9/0x170
   __x64_sys_ioctl+0xc9/0x100
   do_syscall_64+0x47/0xf0
   entry_SYSCALL_64_after_hwframe+0x6f/0x77
  RIP: 0033:0x7f893dde49cf
  Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48
  89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89>
  c2 3d 00 f0 ff ff 77 18 48 8b 44 24 18 64 48 2b 04 25 28 00 00
  RSP: 002b:00007ffc03ff4160 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  RAX: ffffffffffffffda RBX: 00007ffc03ff4378 RCX: 00007f893dde49cf
  RDX: 00007ffc03ff41d0 RSI: 00000000c018cf07 RDI: 0000000000000003
  RBP: 00007ffc03ff4260 R08: 0000000000000410 R09: 0000000000000001
  R10: 00007f893dce7300 R11: 0000000000000246 R12: 0000000000000000
  R13: 00007ffc03ff4388 R14: 00007f893df15000 R15: 0000000000406de0
   </TASK>

Fix this by increasing size of SMB2_QUERY_INFO request buffers and
validating input length to prevent other callers from overflowing @Req
in SMB2_query_info_init() as well.

Fixes: f5b05d6 ("cifs: add IOCTL for QUERY_INFO passthrough to userspace")
Cc: [email protected]
Reported-by: Robert Morris <[email protected]>
Signed-off-by: Paulo Alcantara <[email protected]>
Signed-off-by: Steve French <[email protected]>
pojntfx pushed a commit to loopholelabs/linux-pvm that referenced this issue Oct 18, 2024
…@infineon.com

When sending an email to [email protected], the server
responds '550 virt-pvm#5.1.0 Address rejected.'

Signed-off-by: Lukas Bulwahn <[email protected]>
Signed-off-by: Kalle Valo <[email protected]>
Link: https://msgid.link/[email protected]
pojntfx pushed a commit to loopholelabs/linux-pvm that referenced this issue Oct 18, 2024
Trying to suspend to RAM on SAMA5D27 EVK leads to the following lockdep
warning:

 ============================================
 WARNING: possible recursive locking detected
 6.7.0-rc5-wt+ torvalds#532 Not tainted
 --------------------------------------------
 sh/92 is trying to acquire lock:
 c3cf306c (&irq_desc_lock_class){-.-.}-{2:2}, at: __irq_get_desc_lock+0xe8/0x100

 but task is already holding lock:
 c3d7c46c (&irq_desc_lock_class){-.-.}-{2:2}, at: __irq_get_desc_lock+0xe8/0x100

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(&irq_desc_lock_class);
   lock(&irq_desc_lock_class);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

 6 locks held by sh/92:
  #0: c3aa0258 (sb_writers#6){.+.+}-{0:0}, at: ksys_write+0xd8/0x178
  #1: c4c2df44 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x138/0x284
  virt-pvm#2: c32684a0 (kn->active){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x148/0x284
  virt-pvm#3: c232b6d4 (system_transition_mutex){+.+.}-{3:3}, at: pm_suspend+0x13c/0x4e8
  virt-pvm#4: c387b088 (&dev->mutex){....}-{3:3}, at: __device_suspend+0x1e8/0x91c
  virt-pvm#5: c3d7c46c (&irq_desc_lock_class){-.-.}-{2:2}, at: __irq_get_desc_lock+0xe8/0x100

 stack backtrace:
 CPU: 0 PID: 92 Comm: sh Not tainted 6.7.0-rc5-wt+ torvalds#532
 Hardware name: Atmel SAMA5
  unwind_backtrace from show_stack+0x18/0x1c
  show_stack from dump_stack_lvl+0x34/0x48
  dump_stack_lvl from __lock_acquire+0x19ec/0x3a0c
  __lock_acquire from lock_acquire.part.0+0x124/0x2d0
  lock_acquire.part.0 from _raw_spin_lock_irqsave+0x5c/0x78
  _raw_spin_lock_irqsave from __irq_get_desc_lock+0xe8/0x100
  __irq_get_desc_lock from irq_set_irq_wake+0xa8/0x204
  irq_set_irq_wake from atmel_gpio_irq_set_wake+0x58/0xb4
  atmel_gpio_irq_set_wake from irq_set_irq_wake+0x100/0x204
  irq_set_irq_wake from gpio_keys_suspend+0xec/0x2b8
  gpio_keys_suspend from dpm_run_callback+0xe4/0x248
  dpm_run_callback from __device_suspend+0x234/0x91c
  __device_suspend from dpm_suspend+0x224/0x43c
  dpm_suspend from dpm_suspend_start+0x9c/0xa8
  dpm_suspend_start from suspend_devices_and_enter+0x1e0/0xa84
  suspend_devices_and_enter from pm_suspend+0x460/0x4e8
  pm_suspend from state_store+0x78/0xe4
  state_store from kernfs_fop_write_iter+0x1a0/0x284
  kernfs_fop_write_iter from vfs_write+0x38c/0x6f4
  vfs_write from ksys_write+0xd8/0x178
  ksys_write from ret_fast_syscall+0x0/0x1c
 Exception stack(0xc52b3fa8 to 0xc52b3ff0)
 3fa0:                   00000004 005a0ae8 00000001 005a0ae8 00000004 00000001
 3fc0: 00000004 005a0ae8 00000001 00000004 00000004 b6c616c0 00000020 0059d190
 3fe0: 00000004 b6c61678 aec5a041 aebf1a26

This warning is raised because pinctrl-at91-pio4 uses chained IRQ. Whenever
a wake up source configures an IRQ through irq_set_irq_wake, it will
lock the corresponding IRQ desc, and then call irq_set_irq_wake on "parent"
IRQ which will do the same on its own IRQ desc, but since those two locks
share the same class, lockdep reports this as an issue.

Fix lockdep false positive by setting a different class for parent and
children IRQ

Fixes: 7761808 ("pinctrl: introduce driver for Atmel PIO4 controller")
Signed-off-by: Alexis Lothoré <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Linus Walleij <[email protected]>
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