From: Stanislav Kinsburskii <[email protected]> Sent: Monday, April 27, 2026 7:44 AM > > Restore interrupt state before breaking out of the loop on error. > > The irq_flags are saved before entering the loop, but the early exit > path on error fails to restore them. This leaves interrupts in an > inconsistent state and can lead to lockdep warnings or other > interrupt-related issues. > > Fixes: 621191d709b14 ("Drivers: hv: Introduce mshv_root module to expose > /dev/mshv to VMMs") > Signed-off-by: Stanislav Kinsburskii <[email protected]> > --- > drivers/hv/mshv_root_hv_call.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/hv/mshv_root_hv_call.c b/drivers/hv/mshv_root_hv_call.c > index ab210a7fcb8c3..61291ec6f3468 100644 > --- a/drivers/hv/mshv_root_hv_call.c > +++ b/drivers/hv/mshv_root_hv_call.c > @@ -229,8 +229,10 @@ static int hv_do_map_gpa_hcall(u64 partition_id, u64 > gfn, u64 page_struct_count, > } else { > pfnlist[i] = mmio_spa + done + i; > } > - if (ret) > + if (ret) { > + local_irq_restore(irq_flags); > break; > + } >
This looks good for fixing the immediate bug. But I'd note that this error path occurs solely based on the if (index >= page_struct_count) test in the preceding 'for' loop. That test is a "can't happen" sanity test that never triggers if hv_do_map_gpa_hcall() is coded correctly. At the beginning of the function there are validations of the input arguments, which is reasonable. But this sanity test isn't based on the input arguments, and it adds non-trivial complexity to the code because of the nested loops and the need to figure out where the two "break" statements go. I'd argue for dropping the sanity test entirely, along with this test of 'ret' and the need to restore the interrupt state. Michael
