Commit b1c3497e authored by Jane Malalane's avatar Jane Malalane Committed by Juergen Gross
Browse files

x86/xen: Add support for HVMOP_set_evtchn_upcall_vector 



Implement support for the HVMOP_set_evtchn_upcall_vector hypercall in
order to set the per-vCPU event channel vector callback on Linux and
use it in preference of HVM_PARAM_CALLBACK_IRQ.

If the per-VCPU vector setup is successful on BSP, use this method
for the APs. If not, fallback to the global vector-type callback.

Also register callback_irq at per-vCPU event channel setup to trick
toolstack to think the domain is enlightened.

Suggested-by: default avatar"Roger Pau Monné" <roger.pau@citrix.com>
Signed-off-by: default avatarJane Malalane <jane.malalane@citrix.com>
Reviewed-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/20220729070416.23306-1-jane.malalane@citrix.com


Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
parent 251e90e7

arch/x86/include/asm/xen/cpuid.h

+2 −0
Original line number Diff line number Diff line
@@ -107,6 +107,8 @@ 
 * ID field from 8 to 15 bits, allowing to target APIC IDs up 32768.

 */

#define XEN_HVM_CPUID_EXT_DEST_ID      (1u << 5)

/* Per-vCPU event channel upcalls */

#define XEN_HVM_CPUID_UPCALL_VECTOR    (1u << 6)



/*

 * Leaf 6 (0x40000x05)

arch/x86/include/asm/xen/events.h

+2 −1
Original line number Diff line number Diff line
@@ -23,7 +23,7 @@ static inline int xen_irqs_disabled(struct pt_regs *regs) 
/* No need for a barrier -- XCHG is a barrier on x86. */

#define xchg_xen_ulong(ptr, val) xchg((ptr), (val))



extern int xen_have_vector_callback;

extern bool xen_have_vector_callback;



/*

 * Events delivered via platform PCI interrupts are always
@@ -34,4 +34,5 @@ static inline bool xen_support_evtchn_rebind(void) 
	return (!xen_hvm_domain() || xen_have_vector_callback);

}



extern bool xen_percpu_upcall;

#endif /* _ASM_X86_XEN_EVENTS_H */

arch/x86/xen/enlighten.c

+1 −1
Original line number Diff line number Diff line
@@ -51,7 +51,7 @@ EXPORT_SYMBOL_GPL(xen_start_info); 


struct shared_info xen_dummy_shared_info;



__read_mostly int xen_have_vector_callback;

__read_mostly bool xen_have_vector_callback = true;

EXPORT_SYMBOL_GPL(xen_have_vector_callback);



/*

arch/x86/xen/enlighten_hvm.c

+18 −6
Original line number Diff line number Diff line
@@ -8,6 +8,8 @@ 


#include <xen/features.h>

#include <xen/events.h>

#include <xen/hvm.h>

#include <xen/interface/hvm/hvm_op.h>

#include <xen/interface/memory.h>



#include <asm/apic.h>
@@ -31,6 +33,9 @@ 


static unsigned long shared_info_pfn;



__ro_after_init bool xen_percpu_upcall;

EXPORT_SYMBOL_GPL(xen_percpu_upcall);



void xen_hvm_init_shared_info(void)

{

	struct xen_add_to_physmap xatp;
@@ -126,6 +131,9 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_xen_hvm_callback) 
{

	struct pt_regs *old_regs = set_irq_regs(regs);



	if (xen_percpu_upcall)

		ack_APIC_irq();



	inc_irq_stat(irq_hv_callback_count);



	xen_hvm_evtchn_do_upcall();
@@ -169,6 +177,15 @@ static int xen_cpu_up_prepare_hvm(unsigned int cpu) 
	if (!xen_have_vector_callback)

		return 0;



	if (xen_percpu_upcall) {

		rc = xen_set_upcall_vector(cpu);

		if (rc) {

			WARN(1, "HVMOP_set_evtchn_upcall_vector"

			     " for CPU %d failed: %d\n", cpu, rc);

			return rc;

		}

	}



	if (xen_feature(XENFEAT_hvm_safe_pvclock))

		xen_setup_timer(cpu);
@@ -189,8 +206,6 @@ static int xen_cpu_dead_hvm(unsigned int cpu) 
	return 0;

}



static bool no_vector_callback __initdata;



static void __init xen_hvm_guest_init(void)

{

	if (xen_pv_domain())
@@ -213,9 +228,6 @@ static void __init xen_hvm_guest_init(void) 


	xen_panic_handler_init();



	if (!no_vector_callback && xen_feature(XENFEAT_hvm_callback_vector))

		xen_have_vector_callback = 1;



	xen_hvm_smp_init();

	WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_hvm, xen_cpu_dead_hvm));

	xen_unplug_emulated_devices();
@@ -241,7 +253,7 @@ early_param("xen_nopv", xen_parse_nopv); 


static __init int xen_parse_no_vector_callback(char *arg)

{

	no_vector_callback = true;

	xen_have_vector_callback = false;

	return 0;

}

early_param("xen_no_vector_callback", xen_parse_no_vector_callback);

arch/x86/xen/suspend_hvm.c

+9 −1
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
#include <xen/hvm.h>

#include <xen/features.h>

#include <xen/interface/features.h>

#include <xen/events.h>



#include "xen-ops.h"
@@ -14,6 +15,13 @@ void xen_hvm_post_suspend(int suspend_cancelled) 
		xen_hvm_init_shared_info();

		xen_vcpu_restore();

	}

	if (xen_percpu_upcall) {

		unsigned int cpu;



		for_each_online_cpu(cpu)

			BUG_ON(xen_set_upcall_vector(cpu));

	} else {

		xen_setup_callback_vector();

	}

	xen_unplug_emulated_devices();

}