US 12,455,755 B2
Coordinating timer access for virtual machines using peripheral component interface cards
Michael Tsirkin, Haifa (IL); and Amnon Ilan, Raanana (IL)
Assigned to Red Hat, Inc., Raleigh, NC (US)
Filed by Red Hat, Inc., Raleigh, NC (US)
Filed on Feb. 4, 2022, as Appl. No. 17/592,815.
Prior Publication US 2023/0251883 A1, Aug. 10, 2023
Int. Cl. G06F 9/455 (2018.01); G06F 9/48 (2006.01); G06F 13/16 (2006.01); G06F 13/24 (2006.01); G06F 13/42 (2006.01)
CPC G06F 9/45558 (2013.01) [G06F 9/45545 (2013.01); G06F 9/4812 (2013.01); G06F 13/1668 (2013.01); G06F 13/24 (2013.01); G06F 13/4221 (2013.01); G06F 2009/45562 (2013.01)] 20 Claims
OG exemplary drawing
 
9. A method comprising:
transmitting, by a virtual machine deployed by a hypervisor, a timer request;
in response to receiving the timer request, writing, by a guest driver, a timer for the virtual machine into a first portion of memory on a peripheral component interface (PCI) card, the first portion of memory being mapped to the virtual machine by the hypervisor;
receiving, from the PCI card, a card interrupt for the timer;
translating the card interrupt into a timer interrupt; and
injecting, by the hypervisor, the timer interrupt to the virtual machine while the virtual machine is executing.