From: Nuno Das Neves <nunodasneves@xxxxxxxxxxxxxxxxxxx> Sent: Thursday, February 27, 2025 1:08 PM > > On 2/26/2025 12:06 PM, mhkelley58@xxxxxxxxx wrote: > > From: Michael Kelley <mhklinux@xxxxxxxxxxx> > > > > Update hypercall call sites to use the new hv_hvcall_*() functions > > to set up hypercall arguments. Since these functions zero the > > fixed portion of input memory, remove now redundant calls to memset() > > and explicit zero'ing of input fields. > > > > Signed-off-by: Michael Kelley <mhklinux@xxxxxxxxxxx> > > --- > > arch/x86/hyperv/hv_apic.c | 6 ++---- > > arch/x86/hyperv/hv_init.c | 5 +---- > > arch/x86/hyperv/hv_vtl.c | 8 ++------ > > arch/x86/hyperv/irqdomain.c | 10 ++++------ > > 4 files changed, 9 insertions(+), 20 deletions(-) > > > > diff --git a/arch/x86/hyperv/hv_apic.c b/arch/x86/hyperv/hv_apic.c > > index f022d5f64fb6..c16f81dd36fc 100644 > > --- a/arch/x86/hyperv/hv_apic.c > > +++ b/arch/x86/hyperv/hv_apic.c > > @@ -115,14 +115,12 @@ static bool __send_ipi_mask_ex(const struct cpumask *mask, int vector, > > return false; > > > > local_irq_save(flags); > > - ipi_arg = *this_cpu_ptr(hyperv_pcpu_input_arg); > > - > > + hv_hvcall_in_array(&ipi_arg, sizeof(*ipi_arg), > > + sizeof(ipi_arg->vp_set.bank_contents[0])); > I think the returned "batch size" should be checked to ensure it is not too small to hold the > variable-sized part of the header. Are you saying to check the batch_size against nr_bank (which is the size of the array embedded in vp_set)? > > > if (unlikely(!ipi_arg)) > > goto ipi_mask_ex_done; > > > While here, is this check really needed? If so, maybe a check for the percpu page(s) could be > baked into hv_hvcall_inout_array()? Yes, I wanted to bake the check into hv_hvcall_inout_array(). But this check really is needed. hv_send_ipi(), which can propagate down to __send_ipi_mask_ex(), can get called early during boot before the per-cpu hypercall argument page is allocated. The lack of the hypercall argument page must cleanly propagate back to hv_send_ipi() so it can use the native APIC "send IPI" function that works without a hypercall, but is slower. > > > ipi_arg->vector = vector; > > - ipi_arg->reserved = 0; > > - ipi_arg->vp_set.valid_bank_mask = 0; > > > > /* > > * Use HV_GENERIC_SET_ALL and avoid converting cpumask to VP_SET > > diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c > > index ddeb40930bc8..c5c9511cb7ed 100644 > > --- a/arch/x86/hyperv/hv_init.c > > +++ b/arch/x86/hyperv/hv_init.c > > @@ -400,13 +400,10 @@ static u8 __init get_vtl(void) > > u64 ret; > > > > local_irq_save(flags); > > - input = *this_cpu_ptr(hyperv_pcpu_input_arg); > > - output = *this_cpu_ptr(hyperv_pcpu_output_arg); > > > > - memset(input, 0, struct_size(input, names, 1)); > > + hv_hvcall_inout(&input, sizeof(*input), &output, sizeof(*output)); > > This doesn't look right, this is a rep hypercall taking an array of register names > and outputting an array of register values. > > hv_hvcall_inout_array() should be fully utilized (input and output arrays) here. > > The current code may actually work, but it will overlap the input and output! Yep. I messed this up. Not sure why. :-( Will fix. > > > input->partition_id = HV_PARTITION_ID_SELF; > > input->vp_index = HV_VP_INDEX_SELF; > > - input->input_vtl.as_uint8 = 0; > > input->names[0] = HV_REGISTER_VSM_VP_STATUS; > > > > ret = hv_do_hypercall(control, input, output); > > diff --git a/arch/x86/hyperv/hv_vtl.c b/arch/x86/hyperv/hv_vtl.c > > index 3f4e20d7b724..3dd27d548db6 100644 > > --- a/arch/x86/hyperv/hv_vtl.c > > +++ b/arch/x86/hyperv/hv_vtl.c > <snip> > > @@ -185,13 +184,10 @@ static int hv_vtl_apicid_to_vp_id(u32 apic_id) > > > > local_irq_save(irq_flags); > > > > - input = *this_cpu_ptr(hyperv_pcpu_input_arg); > > - memset(input, 0, sizeof(*input)); > > + hv_hvcall_inout(&input, sizeof(*input), &output, sizeof(*output)); > This has the same issue as above - it is a rep hypercall so needs hv_hvcall_inout_array() Agreed. Will fix. > > > input->partition_id = HV_PARTITION_ID_SELF; > > input->apic_ids[0] = apic_id; > > > > - output = *this_cpu_ptr(hyperv_pcpu_output_arg); > > - > > control = HV_HYPERCALL_REP_COMP_1 | HVCALL_GET_VP_ID_FROM_APIC_ID; > > status = hv_do_hypercall(control, input, output); > > ret = output[0]; > > diff --git a/arch/x86/hyperv/irqdomain.c b/arch/x86/hyperv/irqdomain.c > > index 64b921360b0f..803b1a945c5c 100644 > > --- a/arch/x86/hyperv/irqdomain.c > > +++ b/arch/x86/hyperv/irqdomain.c > > @@ -24,11 +24,11 @@ static int hv_map_interrupt(union hv_device_id device_id, bool level, > > > > local_irq_save(flags); > > > > - input = *this_cpu_ptr(hyperv_pcpu_input_arg); > > - output = *this_cpu_ptr(hyperv_pcpu_output_arg); > > + hv_hvcall_inout_array(&input, sizeof(*input), > > + sizeof(input->interrupt_descriptor.target.vp_set.bank_contents[0]), > > + &output, sizeof(*output), 0); > As noted before I think the batch size should be checked to ensure it is large enough. > > Side note - it seems in this hypercall, nr_banks + 1 is used as the varhead size, which > counts the vp valid mask, but this is not the case in __send_ipi_mask_ex(). Do you happen > to know why that might be? Interesting discrepancy. Right off the bat, I don't know why. The comment in hv_map_interrupt() is very specific and sounds like it knows what it is talking about. hyperv_flush_tlb_others_ex() does it like __send_ipi_mask_ex(), but hv_arch_irq_unmask() does it like hv_map_interrupt(), and with the same comment. So two votes for each way. :-( I'll research further. Thanks for the careful review and flagging the mistakes! Michael
