| Message ID | 1740611284-27506-8-git-send-email-nunodasneves@linux.microsoft.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Introduce /dev/mshv root partition driver | expand |
On Wed, Feb 26, 2025 at 03:08:01PM -0800, Nuno Das Neves wrote: > Add a pointer hv_synic_eventring_tail to track the tail pointer for the > SynIC event ring buffer for each SINT. > > This will be used by the mshv driver, but must be tracked independently > since the driver module could be removed and re-inserted. > > Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> > Reviewed-by: Wei Liu <wei.liu@kernel.org> > --- > drivers/hv/hv_common.c | 34 ++++++++++++++++++++++++++++++++-- > 1 file changed, 32 insertions(+), 2 deletions(-) > > diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c > index 252fd66ad4db..2763cb6d3678 100644 > --- a/drivers/hv/hv_common.c > +++ b/drivers/hv/hv_common.c > @@ -460,6 +478,7 @@ void __init ms_hyperv_late_init(void) > int hv_common_cpu_init(unsigned int cpu) > { > void **inputarg, **outputarg; > + u8 **synic_eventring_tail; > u64 msr_vp_index; > gfp_t flags; > const int pgcount = hv_output_page_exists() ? 2 : 1; > @@ -472,8 +491,8 @@ int hv_common_cpu_init(unsigned int cpu) > inputarg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg); > > /* > - * hyperv_pcpu_input_arg and hyperv_pcpu_output_arg memory is already > - * allocated if this CPU was previously online and then taken offline > + * The per-cpu memory is already allocated if this CPU was previously > + * online and then taken offline > */ > if (!*inputarg) { > mem = kmalloc(pgcount * HV_HYP_PAGE_SIZE, flags); > @@ -485,6 +504,17 @@ int hv_common_cpu_init(unsigned int cpu) > *outputarg = (char *)mem + HV_HYP_PAGE_SIZE; > } > > + if (hv_root_partition()) { > + synic_eventring_tail = (u8 **)this_cpu_ptr(hv_synic_eventring_tail); > + *synic_eventring_tail = kcalloc(HV_SYNIC_SINT_COUNT, > + sizeof(u8), flags); > + Redundant empty line ^^^ > + if (unlikely(!*synic_eventring_tail)) { > + kfree(mem); > + return -ENOMEM; > + } > + } > + > if (!ms_hyperv.paravisor_present && > (hv_isolation_type_snp() || hv_isolation_type_tdx())) { > ret = set_memory_decrypted((unsigned long)mem, pgcount); Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> > -- > 2.34.1 >
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c index 252fd66ad4db..2763cb6d3678 100644 --- a/drivers/hv/hv_common.c +++ b/drivers/hv/hv_common.c @@ -68,6 +68,16 @@ static void hv_kmsg_dump_unregister(void); static struct ctl_table_header *hv_ctl_table_hdr; +/* + * Per-cpu array holding the tail pointer for the SynIC event ring buffer + * for each SINT. + * + * We cannot maintain this in mshv driver because the tail pointer should + * persist even if the mshv driver is unloaded. + */ +u8 __percpu **hv_synic_eventring_tail; +EXPORT_SYMBOL_GPL(hv_synic_eventring_tail); + /* * Hyper-V specific initialization and shutdown code that is * common across all architectures. Called from architecture @@ -90,6 +100,9 @@ void __init hv_common_free(void) free_percpu(hyperv_pcpu_input_arg); hyperv_pcpu_input_arg = NULL; + + free_percpu(hv_synic_eventring_tail); + hv_synic_eventring_tail = NULL; } /* @@ -372,6 +385,11 @@ int __init hv_common_init(void) BUG_ON(!hyperv_pcpu_output_arg); } + if (hv_root_partition()) { + hv_synic_eventring_tail = alloc_percpu(u8 *); + BUG_ON(hv_synic_eventring_tail == NULL); + } + hv_vp_index = kmalloc_array(nr_cpu_ids, sizeof(*hv_vp_index), GFP_KERNEL); if (!hv_vp_index) { @@ -460,6 +478,7 @@ void __init ms_hyperv_late_init(void) int hv_common_cpu_init(unsigned int cpu) { void **inputarg, **outputarg; + u8 **synic_eventring_tail; u64 msr_vp_index; gfp_t flags; const int pgcount = hv_output_page_exists() ? 2 : 1; @@ -472,8 +491,8 @@ int hv_common_cpu_init(unsigned int cpu) inputarg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg); /* - * hyperv_pcpu_input_arg and hyperv_pcpu_output_arg memory is already - * allocated if this CPU was previously online and then taken offline + * The per-cpu memory is already allocated if this CPU was previously + * online and then taken offline */ if (!*inputarg) { mem = kmalloc(pgcount * HV_HYP_PAGE_SIZE, flags); @@ -485,6 +504,17 @@ int hv_common_cpu_init(unsigned int cpu) *outputarg = (char *)mem + HV_HYP_PAGE_SIZE; } + if (hv_root_partition()) { + synic_eventring_tail = (u8 **)this_cpu_ptr(hv_synic_eventring_tail); + *synic_eventring_tail = kcalloc(HV_SYNIC_SINT_COUNT, + sizeof(u8), flags); + + if (unlikely(!*synic_eventring_tail)) { + kfree(mem); + return -ENOMEM; + } + } + if (!ms_hyperv.paravisor_present && (hv_isolation_type_snp() || hv_isolation_type_tdx())) { ret = set_memory_decrypted((unsigned long)mem, pgcount);