kvm tools: Add kvm__arch_periodic_poll()

Currently, the SIGALRM handler calls device poll functions (for serial, virtio
console) directly.  Which devices are present and which require polling is a
system-specific decision, so create a new function called from common code &
move the x86-specific poll calls into it.

Signed-off-by: Matt Evans <matt@ozlabs.org>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

builtin-run.c

@@ -522,8 +522,7 @@ static void handle_debug(int fd, u32 type, u32 len, u8 *msg)
 
 static void handle_sigalrm(int sig)
 {
-	serial8250__inject_interrupt(kvm);
-	virtio_console__inject_interrupt(kvm);
+	kvm__arch_periodic_poll(kvm);
 }
 
 static void handle_stop(int fd, u32 type, u32 len, u8 *msg)

include/kvm/kvm.h

@@ -56,6 +56,7 @@ void kvm__remove_socket(const char *name);
 void kvm__arch_init(struct kvm *kvm, const char *kvm_dev, u64 ram_size, const char *name);
 void kvm__arch_setup_firmware(struct kvm *kvm);
 bool kvm__arch_cpu_supports_vm(void);
+void kvm__arch_periodic_poll(struct kvm *kvm);
 
 int load_flat_binary(struct kvm *kvm, int fd);
 bool load_bzimage(struct kvm *kvm, int fd_kernel, int fd_initrd, const char *kernel_cmdline, u16 vidmode);

x86/kvm.c

@@ -4,6 +4,8 @@
 #include "kvm/interrupt.h"
 #include "kvm/mptable.h"
 #include "kvm/util.h"
+#include "kvm/8250-serial.h"
+#include "kvm/virtio-console.h"
 
 #include <asm/bootparam.h>
 #include <linux/kvm.h>
@@ -328,3 +330,9 @@ void kvm__arch_setup_firmware(struct kvm *kvm)
 	/* MP table */
 	mptable_setup(kvm, kvm->nrcpus);
 }
+
+void kvm__arch_periodic_poll(struct kvm *kvm)
+{
+	serial8250__inject_interrupt(kvm);
+	virtio_console__inject_interrupt(kvm);
+}