@@ -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);