vmm: interrupt: fix msi mask irq causing kernel panic on AMD

When mask a msi irq, we set the entry.masked to be true, so kvm
hypervisor will not pass the gsi to kernel through KVM_SET_GSI_ROUTING
ioctl which update kvm->irq_routing. This will trigger kernel
panic on AMD platform when the gsi is the largest one in kernel
kvm->irqfds.items:

crash> bt
PID: 22218  TASK: ffff951a6ad74980  CPU: 73  COMMAND: "vcpu8"
 #0 [ffffb1ba6707fa40] machine_kexec at ffffffff8565b397
 #1 [ffffb1ba6707fa90] __crash_kexec at ffffffff85788a6d
 #2 [ffffb1ba6707fb58] crash_kexec at ffffffff8578995d
 #3 [ffffb1ba6707fb70] oops_end at ffffffff85623c0d
 #4 [ffffb1ba6707fb90] no_context at ffffffff856692c9
 #5 [ffffb1ba6707fbf8] exc_page_fault at ffffffff85f95b51
 #6 [ffffb1ba6707fc50] asm_exc_page_fault at ffffffff86000ace
    [exception RIP: svm_update_pi_irte+227]
    RIP: ffffffffc0761b53  RSP: ffffb1ba6707fd08  RFLAGS: 00010086
    RAX: ffffb1ba6707fd78  RBX: ffffb1ba66d91000  RCX: 0000000000000001
    RDX: 00003c803f63f1c0  RSI: 000000000000019a  RDI: ffffb1ba66db2ab8
    RBP: 000000000000019a   R8: 0000000000000040   R9: ffff94ca41b82200
    R10: ffffffffffffffcf  R11: 0000000000000001  R12: 0000000000000001
    R13: 0000000000000001  R14: ffffffffffffffcf  R15: 000000000000005f
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #7 [ffffb1ba6707fdb8] kvm_irq_routing_update at ffffffffc09f19a1 [kvm]
 #8 [ffffb1ba6707fde0] kvm_set_irq_routing at ffffffffc09f2133 [kvm]
 #9 [ffffb1ba6707fe18] kvm_vm_ioctl at ffffffffc09ef544 [kvm]
    RIP: 00007f143c36488b  RSP: 00007f143a4e04b8  RFLAGS: 00000246
    RAX: ffffffffffffffda  RBX: 00007f05780041d0  RCX: 00007f143c36488b
    RDX: 00007f05780041d0  RSI: 000000004008ae6a  RDI: 0000000000000020
    RBP: 00000000000004e8   R8: 0000000000000008   R9: 00007f05780041e0
    R10: 00007f0578004560  R11: 0000000000000246  R12: 00000000000004e0
    R13: 000000000000001a  R14: 00007f1424001c60  R15: 00007f0578003bc0
    ORIG_RAX: 0000000000000010  CS: 0033  SS: 002b

To solve this problem, move route.disable() before set_gsi_routes() to
remove the gsi from irqfds.items first.

This problem only exists on AMD platform, 'cause on Intel platform
kernel just return when update irte while it only prints a warning on
AMD.

Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
(cherry picked from commit db9e5e5a87)
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
This commit is contained in:
Yi Wang 2022-03-08 19:04:24 +08:00 committed by Rob Bradford
parent bbda07c388
commit 4dfe1ff77a

View File

@ -190,8 +190,8 @@ impl InterruptSourceGroup for MsiInterruptGroup<IrqRoutingEntry> {
format!("mask: No existing route for interrupt index {}", index),
));
}
self.set_gsi_routes(&routes)?;
return route.disable(&self.vm);
route.disable(&self.vm)?;
return self.set_gsi_routes(&routes);
}
Err(io::Error::new(