2e53b0b450
Add property "ioeventfd" which is enabled by default. When this is enabled, updates on the doorbell registers will cause KVM to signal an event to the QEMU main loop to handle the doorbell updates. Therefore, instead of letting the vcpu thread run both guest VM and IO emulation, we now use the main loop thread to do IO emulation and thus the vcpu thread has more cycles for the guest VM. Since ioeventfd does not tell us the exact value that is written, it is only useful when shadow doorbell buffer is enabled, where we check for the value in the shadow doorbell buffer when we get the doorbell update event. IOPS comparison on Linux 5.19-rc2: (Unit: KIOPS) qd 1 4 16 64 qemu 35 121 176 153 ioeventfd 41 133 258 313 Changes since v3: - Do not deregister ioeventfd when it was not enabled on a SQ/CQ Signed-off-by: Jinhao Fan <fanjinhao21s@ict.ac.cn> Reviewed-by: Klaus Jensen <k.jensen@samsung.com> Signed-off-by: Klaus Jensen <k.jensen@samsung.com> |
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| .. | ||
| ctrl.c | ||
| dif.c | ||
| dif.h | ||
| Kconfig | ||
| meson.build | ||
| ns.c | ||
| nvme.h | ||
| subsys.c | ||
| trace-events | ||
| trace.h | ||