On Fri, Jul 11, 2025 at 2:16 PM Radim Krčmář <rkrcmar@xxxxxxxxxxxxxxxx> wrote: > > 2025-07-10T21:30:30+08:00, Xu Lu <luxu.kernel@xxxxxxxxxxxxx>: > > Delegate faults which are not handled by kvm to VS mode to avoid > > unnecessary traps to HS mode. These faults include illegal instruction > > fault, instruction access fault, load access fault and store access > > fault. > > > > The delegation of illegal instruction fault is particularly important > > to guest applications that use vector instructions frequently. In such > > cases, an illegal instruction fault will be raised when guest user thread > > uses vector instruction the first time and then guest kernel will enable > > user thread to execute following vector instructions. > > (This optimization will be even more significant when nesting, where it > would currently go -> HS0 -> HS1 -> HS0 -> VS1, instead of -> VS1.) Nice supplement! Thanks. > > > The fw pmu event counters remain undeleted so that guest can still get > > these events via sbi call. Guest will only see zero count on these > > events and know 'firmware' has delegated these faults. > > > > Signed-off-by: Xu Lu <luxu.kernel@xxxxxxxxxxxxx> > > --- > > Reviewed-by: Radim Krčmář <rkrcmar@xxxxxxxxxxxxxxxx>
