kvm tools: support injecting arbitrary sysrqs

Add support to 'lkvm debug' to inject arbitrary sysrqs using a new
'-s <sysrq>' argument.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

diff --git a/tools/kvm/builtin-debug.c b/tools/kvm/builtin-debug.c
index 20e27ff980f145638d5b06d94fc34ac7db06869a..4ae51d200374b46ffeb96da786cc0ff9271894d7 100644 (file)
--- a/tools/kvm/builtin-debug.c
+++ b/tools/kvm/builtin-debug.c
@@ -16,6 +16,7 @@ static bool all;
 static int nmi = -1;
 static bool dump;
 static const char *instance_name;
+static const char *sysrq;
 
 static const char * const debug_usage[] = {
        "lkvm debug [--all] [-n name] [-d] [-m vcpu]",
@@ -26,6 +27,7 @@ static const struct option debug_options[] = {
        OPT_GROUP("General options:"),
        OPT_BOOLEAN('d', "dump", &dump, "Generate a debug dump from guest"),
        OPT_INTEGER('m', "nmi", &nmi, "Generate NMI on VCPU"),
+       OPT_STRING('s', "sysrq", &sysrq, "sysrq", "Inject a sysrq"),
        OPT_GROUP("Instance options:"),
        OPT_BOOLEAN('a', "all", &all, "Debug all instances"),
        OPT_STRING('n', "name", &instance_name, "name", "Instance name"),
@@ -61,6 +63,11 @@ static int do_debug(const char *name, int sock)
                cmd.cpu = nmi;
        }
 
+       if (sysrq) {
+               cmd.dbg_type |= KVM_DEBUG_CMD_TYPE_SYSRQ;
+               cmd.sysrq = sysrq[0];
+       }
+
        r = kvm_ipc__send_msg(sock, KVM_IPC_DEBUG, sizeof(cmd), (u8 *)&cmd);
        if (r < 0)
                return r;

diff --git a/tools/kvm/builtin-run.c b/tools/kvm/builtin-run.c
index a120fe27ab3b0aaeb84e905c81cf15df5b33d294..21d5f341f5d00ba22132e221b564f1f53f3ea34f 100644 (file)
--- a/tools/kvm/builtin-run.c
+++ b/tools/kvm/builtin-run.c
@@ -557,6 +557,9 @@ static void handle_debug(int fd, u32 type, u32 len, u8 *msg)
        dbg_type = params->dbg_type;
        vcpu = params->cpu;
 
+       if (dbg_type & KVM_DEBUG_CMD_TYPE_SYSRQ)
+               serial8250__inject_sysrq(kvm, params->sysrq);
+
        if (dbg_type & KVM_DEBUG_CMD_TYPE_NMI) {
                if ((int)vcpu >= kvm->nrcpus)
                        return;
@@ -589,7 +592,7 @@ static void handle_debug(int fd, u32 type, u32 len, u8 *msg)
 
        close(fd);
 
-       serial8250__inject_sysrq(kvm);
+       serial8250__inject_sysrq(kvm, 'p');
 }
 
 static void handle_sigalrm(int sig)

diff --git a/tools/kvm/hw/serial.c b/tools/kvm/hw/serial.c
index 852aea423c8aa1a2c3fd735126d9f5718e50f637..956307c5d539a953017a5e7170cfcdc27e99bcc5 100644 (file)
--- a/tools/kvm/hw/serial.c
+++ b/tools/kvm/hw/serial.c
@@ -153,14 +153,13 @@ static void serial8250_update_irq(struct kvm *kvm, struct serial8250_device *dev
 }
 
 #define SYSRQ_PENDING_NONE             0
-#define SYSRQ_PENDING_BREAK            1
 
 static int sysrq_pending;
 
 static void serial8250__sysrq(struct kvm *kvm, struct serial8250_device *dev)
 {
        dev->lsr |= UART_LSR_DR | UART_LSR_BI;
-       dev->rxbuf[dev->rxcnt++] = 'p';
+       dev->rxbuf[dev->rxcnt++] = sysrq_pending;
        sysrq_pending   = SYSRQ_PENDING_NONE;
 }
 
@@ -219,9 +218,9 @@ void serial8250__update_consoles(struct kvm *kvm)
        }
 }
 
-void serial8250__inject_sysrq(struct kvm *kvm)
+void serial8250__inject_sysrq(struct kvm *kvm, char sysrq)
 {
-       sysrq_pending   = SYSRQ_PENDING_BREAK;
+       sysrq_pending = sysrq;
 }
 
 static struct serial8250_device *find_device(u16 port)

diff --git a/tools/kvm/include/kvm/8250-serial.h b/tools/kvm/include/kvm/8250-serial.h
index df8ef5308385372a13b74f6ae8a920af08a6790d..e9545517351cf7b878679d8d84ed0298c3db62fa 100644 (file)
--- a/tools/kvm/include/kvm/8250-serial.h
+++ b/tools/kvm/include/kvm/8250-serial.h
@@ -6,6 +6,6 @@ struct kvm;
 int serial8250__init(struct kvm *kvm);
 int serial8250__exit(struct kvm *kvm);
 void serial8250__update_consoles(struct kvm *kvm);
-void serial8250__inject_sysrq(struct kvm *kvm);
+void serial8250__inject_sysrq(struct kvm *kvm, char sysrq);
 
 #endif /* KVM__8250_SERIAL_H */

diff --git a/tools/kvm/include/kvm/builtin-debug.h b/tools/kvm/include/kvm/builtin-debug.h
index 6105a8c487c06a34039820ed8563cc081cf3c83c..efa0268402b3a45afa2f63eca41d9e923d9bf373 100644 (file)
--- a/tools/kvm/include/kvm/builtin-debug.h
+++ b/tools/kvm/include/kvm/builtin-debug.h
@@ -6,10 +6,12 @@
 
 #define KVM_DEBUG_CMD_TYPE_DUMP        (1 << 0)
 #define KVM_DEBUG_CMD_TYPE_NMI (1 << 1)
+#define KVM_DEBUG_CMD_TYPE_SYSRQ (1 << 2)
 
 struct debug_cmd_params {
        u32 dbg_type;
        u32 cpu;
+       char sysrq;
 };
 
 int kvm_cmd_debug(int argc, const char **argv, const char *prefix);