accel/mshv: install dummy handler for SIG_IPI
This is similar to HVF's implementation. We want to interrupt the blocking vcpu run. The self-kick was effectively a no-op for mshv. Signed-off-by: Magnus Kulke <magnuskulke@linux.microsoft.com> Reviewed-by: Doru Blânzeanu <dblanzeanu@linux.microsoft.com> Link: https://lore.kernel.org/r/20260710101534.664604-5-magnuskulke@linux.microsoft.com Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Magnus Kulke committed
Jul 10, 2026 at 12:15 UTC
2f6c2ede4688f90a3583cfb2050de66a100fc5cb
1 file changed
+6
-10
accel/mshv/mshv-all.c
+6
-10
@@ -621,17 +621,13 @@ static int mshv_cpu_exec(CPUState *cpu)
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}
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/*
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- * The signal handler is triggered when QEMU's main thread receives a SIG_IPI
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- * (SIGUSR1). This signal causes the current CPU thread to be kicked, forcing a
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- * VM exit on the CPU. The VM exit generates an exit reason that breaks the loop
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- * (see mshv_cpu_exec). If the exit is due to a Ctrl+A+x command, the system
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- * will shut down. For other cases, the system will continue running.
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+ * We need a dummy handler to make SIG_IPI a deliverable signal. The kernel
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+ * handler will be woken up by the caught signal and instruct the hypervisor
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+ * to suspend execution (the concrete mechanism differs between schedulers)
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+ * and return to userspace.
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*/
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-static void sa_ipi_handler(int sig)
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+static void dummy_handler(int sig)
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{
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- /* TODO: call IOCTL to set_immediate_exit, once implemented. */
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-
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- qemu_cpu_kick_self();
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}
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static void init_signal(CPUState *cpu)
@@ -641,7 +637,7 @@ static void init_signal(CPUState *cpu)
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sigset_t set;
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memset(&sigact, 0, sizeof(sigact));
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- sigact.sa_handler = sa_ipi_handler;
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+ sigact.sa_handler = dummy_handler;
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sigaction(SIG_IPI, &sigact, NULL);
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pthread_sigmask(SIG_BLOCK, NULL, &set);