[18/23] hyperv: add synic event flag signaling

Commit Message

Roman Kagan June 6, 2017, 6:19 p.m. UTC

Add infrastructure to signal SynIC event flags by atomically setting the
corresponding bit in the event flags page and firing a SINT if
necessary.

Signed-off-by: Roman Kagan <[e-mail]>
---
 target/i386/hyperv.h |  2 ++
 target/i386/hyperv.c | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+)

Comments

Paolo Bonzini June 14, 2017, 3:07 p.m. UTC | #1

On 06/06/2017 20:19, Roman Kagan wrote:
> +
> +    if ((atomic_fetch_or(&flags[set_idx], set_mask) & set_mask) != set_mask) {
> +        ret = kvm_hv_sint_route_set_sint(sint_route);
> +        memory_region_set_dirty(&synic->evt_page_mr, 0,
> +                                sizeof(*synic->evt_page));

I would swap the kvm_hv_sint_route_set_sint and memory_region_set_dirty
lines.

Paolo

> +    } else {
> +        ret = 0;
> +    }

Patch

diff --git a/target/i386/hyperv.h b/target/i386/hyperv.h
index fa3e988..a2d4304 100644
--- a/target/i386/hyperv.h
+++ b/target/i386/hyperv.h
@@ -39,4 +39,6 @@  void hyperv_synic_update(X86CPU *cpu);
 
 int hyperv_post_msg(HvSintRoute *sint_route, struct hyperv_message *msg);
 
+int hyperv_set_evt_flag(HvSintRoute *sint_route, unsigned evtno);
+
 #endif
diff --git a/target/i386/hyperv.c b/target/i386/hyperv.c
index 0a7f9b1..dcf49e4 100644
--- a/target/i386/hyperv.c
+++ b/target/i386/hyperv.c
@@ -17,6 +17,7 @@ 
 #include "hw/qdev-properties.h"
 #include "exec/address-spaces.h"
 #include "sysemu/cpus.h"
+#include "qemu/bitops.h"
 #include "migration/vmstate.h"
 #include "hyperv.h"
 #include "hyperv_proto.h"
@@ -189,6 +190,37 @@  int hyperv_post_msg(HvSintRoute *sint_route, struct hyperv_message *src_msg)
     return 0;
 }
 
+/*
+ * Set given event flag for a given sint on a given vcpu, and signal the sint.
+ */
+int hyperv_set_evt_flag(HvSintRoute *sint_route, unsigned evtno)
+{
+    int ret;
+    SynICState *synic = sint_route->synic;
+    unsigned long *flags, set_mask;
+    unsigned set_idx;
+
+    if (evtno > HV_EVENT_FLAGS_COUNT) {
+        return -EINVAL;
+    }
+    if (!synic->enabled || !synic->evt_page_addr) {
+        return -ENXIO;
+    }
+
+    set_idx = BIT_WORD(evtno);
+    set_mask = BIT_MASK(evtno);
+    flags = synic->evt_page->slot[sint_route->sint].flags;
+
+    if ((atomic_fetch_or(&flags[set_idx], set_mask) & set_mask) != set_mask) {
+        ret = kvm_hv_sint_route_set_sint(sint_route);
+        memory_region_set_dirty(&synic->evt_page_mr, 0,
+                                sizeof(*synic->evt_page));
+    } else {
+        ret = 0;
+    }
+    return ret;
+}
+
 static void async_synic_update(CPUState *cs, run_on_cpu_data data)
 {
     SynICState *synic = data.host_ptr;