Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 248e742a authored by Michael Kelley's avatar Michael Kelley Committed by Greg Kroah-Hartman
Browse files

Drivers: hv: vmbus: Implement Direct Mode for stimer0 



The 2016 version of Hyper-V offers the option to operate the guest VM
per-vcpu stimer's in Direct Mode, which means the timer interupts on its
own vector rather than queueing a VMbus message. Direct Mode reduces
timer processing overhead in both the hypervisor and the guest, and
avoids having timer interrupts pollute the VMbus interrupt stream for
the synthetic NIC and storage.  This patch enables Direct Mode by
default on stimer0 when running on a version of Hyper-V that supports
it.

In prep for coming support of Hyper-V on ARM64, the arch independent
portion of the code contains calls to routines that will be populated
on ARM64 but are not needed and do nothing on x86.

Signed-off-by: default avatarMichael Kelley <mikelley@microsoft.com>
Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ce767047

arch/x86/entry/entry_32.S

+3 −0
Original line number Diff line number Diff line
@@ -902,6 +902,9 @@ BUILD_INTERRUPT3(hyperv_callback_vector, HYPERVISOR_CALLBACK_VECTOR, 
BUILD_INTERRUPT3(hyperv_reenlightenment_vector, HYPERV_REENLIGHTENMENT_VECTOR,

		 hyperv_reenlightenment_intr)



BUILD_INTERRUPT3(hv_stimer0_callback_vector, HYPERV_STIMER0_VECTOR,

		 hv_stimer0_vector_handler)



#endif /* CONFIG_HYPERV */



ENTRY(page_fault)

arch/x86/entry/entry_64.S

+3 −0
Original line number Diff line number Diff line
@@ -1135,6 +1135,9 @@ apicinterrupt3 HYPERVISOR_CALLBACK_VECTOR \ 


apicinterrupt3 HYPERV_REENLIGHTENMENT_VECTOR \

	hyperv_reenlightenment_vector hyperv_reenlightenment_intr



apicinterrupt3 HYPERV_STIMER0_VECTOR \

	hv_stimer0_callback_vector hv_stimer0_vector_handler

#endif /* CONFIG_HYPERV */



idtentry debug			do_debug		has_error_code=0	paranoid=1 shift_ist=DEBUG_STACK

arch/x86/include/asm/hardirq.h

+1 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ typedef struct { 
#endif

#if IS_ENABLED(CONFIG_HYPERV)

	unsigned int irq_hv_reenlightenment_count;

	unsigned int hyperv_stimer0_count;

#endif

} ____cacheline_aligned irq_cpustat_t;

arch/x86/include/asm/irq_vectors.h

+2 −1
Original line number Diff line number Diff line
@@ -106,9 +106,10 @@ 


#if IS_ENABLED(CONFIG_HYPERV)

#define HYPERV_REENLIGHTENMENT_VECTOR	0xee

#define HYPERV_STIMER0_VECTOR		0xed

#endif



#define LOCAL_TIMER_VECTOR		0xed

#define LOCAL_TIMER_VECTOR		0xec



#define NR_VECTORS			 256

arch/x86/include/asm/mshyperv.h

+13 −0
Original line number Diff line number Diff line
@@ -173,6 +173,19 @@ void hv_remove_kexec_handler(void); 
void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs));

void hv_remove_crash_handler(void);



/*

 * Routines for stimer0 Direct Mode handling.

 * On x86/x64, there are no percpu actions to take.

 */

void hv_stimer0_vector_handler(struct pt_regs *regs);

void hv_stimer0_callback_vector(void);

int hv_setup_stimer0_irq(int *irq, int *vector, void (*handler)(void));

void hv_remove_stimer0_irq(int irq);



static inline void hv_enable_stimer0_percpu_irq(int irq) {}

static inline void hv_disable_stimer0_percpu_irq(int irq) {}





#if IS_ENABLED(CONFIG_HYPERV)

extern struct clocksource *hyperv_cs;

extern void *hv_hypercall_pg;