AuxXxilium/linux_dsm_epyc7002
1
0
Fork 0
mirror of https://github.com/AuxXxilium/linux_dsm_epyc7002.git synced 2024-11-24 10:10:54 +07:00
Code Issues Actions Packages Projects Releases Wiki Activity

KVM: x86: Switch KVM guest to using interrupts for page ready APF delivery

Browse Source 
KVM now supports using interrupt for 'page ready' APF event delivery and
legacy mechanism was deprecated. Switch KVM guests to the new one.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200525144125.143875-9-vkuznets@redhat.com>
[Use HYPERVISOR_CALLBACK_VECTOR instead of a separate vector. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Vitaly Kuznetsov 2020-05-25 16:41:23 +02:00 committed by Paolo Bonzini
parent 49b3deaad3
commit b1d405751c
5 changed files with 52 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/x86/Kconfig
View File

@ -801,6 +801,7 @@ config KVM_GUEST
depends on PARAVIRT
select PARAVIRT_CLOCK
select ARCH_CPUIDLE_HALTPOLL
select X86_HV_CALLBACK_VECTOR
default y
---help---
This option enables various optimizations for running under the KVM

5
arch/x86/entry/entry_32.S
View File

@ -1475,6 +1475,11 @@ BUILD_INTERRUPT3(hv_stimer0_callback_vector, HYPERV_STIMER0_VECTOR,
#endif /* CONFIG_HYPERV */
#ifdef CONFIG_KVM_GUEST
BUILD_INTERRUPT3(kvm_async_pf_vector, HYPERVISOR_CALLBACK_VECTOR,
kvm_async_pf_intr)
#endif
SYM_CODE_START(page_fault)
ASM_CLAC
pushl $do_page_fault

5
arch/x86/entry/entry_64.S
View File

@ -1190,6 +1190,11 @@ apicinterrupt3 HYPERVISOR_CALLBACK_VECTOR \
acrn_hv_callback_vector acrn_hv_vector_handler
#endif
#ifdef CONFIG_KVM_GUEST
apicinterrupt3 HYPERVISOR_CALLBACK_VECTOR \
kvm_async_pf_vector kvm_async_pf_intr
#endif
idtentry debug do_debug has_error_code=0 paranoid=1 shift_ist=IST_INDEX_DB ist_offset=DB_STACK_OFFSET
idtentry int3 do_int3 has_error_code=0 create_gap=1
idtentry stack_segment do_stack_segment has_error_code=1

7
arch/x86/include/asm/kvm_para.h
View File

@ -4,6 +4,7 @@
#include <asm/processor.h>
#include <asm/alternative.h>
#include <linux/interrupt.h>
#include <uapi/asm/kvm_para.h>
extern void kvmclock_init(void);
@ -104,6 +105,12 @@ static __always_inline bool kvm_handle_async_pf(struct pt_regs *regs, u32 token)
return false;
}
extern __visible void kvm_async_pf_vector(void);
#ifdef CONFIG_TRACING
#define trace_kvm_async_pf_vector kvm_async_pf_vector
#endif
__visible void __irq_entry kvm_async_pf_intr(struct pt_regs *regs);
#ifdef CONFIG_PARAVIRT_SPINLOCKS
void __init kvm_spinlock_init(void);
#else /* !CONFIG_PARAVIRT_SPINLOCKS */

50
arch/x86/kernel/kvm.c
View File

@ -233,15 +233,10 @@ NOKPROBE_SYMBOL(kvm_read_and_reset_apf_flags);
bool __kvm_handle_async_pf(struct pt_regs *regs, u32 token)
{
u32 reason = kvm_read_and_reset_apf_flags();
u32 flags = kvm_read_and_reset_apf_flags();
switch (reason) {
case KVM_PV_REASON_PAGE_NOT_PRESENT:
case KVM_PV_REASON_PAGE_READY:
break;
default:
if (!flags)
return false;
}
/*
* If the host managed to inject an async #PF into an interrupt
@ -251,20 +246,39 @@ bool __kvm_handle_async_pf(struct pt_regs *regs, u32 token)
if (unlikely(!(regs->flags & X86_EFLAGS_IF)))
panic("Host injected async #PF in interrupt disabled region\n");
if (reason == KVM_PV_REASON_PAGE_NOT_PRESENT) {
if (flags & KVM_PV_REASON_PAGE_NOT_PRESENT) {
if (unlikely(!(user_mode(regs))))
panic("Host injected async #PF in kernel mode\n");
/* Page is swapped out by the host. */
kvm_async_pf_task_wait_schedule(token);
} else {
rcu_irq_enter();
kvm_async_pf_task_wake(token);
rcu_irq_exit();
return true;
}
WARN_ONCE(1, "Unexpected async PF flags: %x\n", flags);
return true;
}
NOKPROBE_SYMBOL(__kvm_handle_async_pf);
__visible void __irq_entry kvm_async_pf_intr(struct pt_regs *regs)
{
u32 token;
entering_ack_irq();
inc_irq_stat(irq_hv_callback_count);
if (__this_cpu_read(apf_reason.enabled)) {
token = __this_cpu_read(apf_reason.token);
rcu_irq_enter();
kvm_async_pf_task_wake(token);
rcu_irq_exit();
__this_cpu_write(apf_reason.token, 0);
wrmsrl(MSR_KVM_ASYNC_PF_ACK, 1);
}
exiting_irq();
}
static void __init paravirt_ops_setup(void)
{
pv_info.name = "KVM";
@ -308,17 +322,19 @@ static notrace void kvm_guest_apic_eoi_write(u32 reg, u32 val)
static void kvm_guest_cpu_init(void)
{
if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF) && kvmapf) {
u64 pa;
if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF_INT) && kvmapf) {
u64 pa = slow_virt_to_phys(this_cpu_ptr(&apf_reason));
WARN_ON_ONCE(!static_branch_likely(&kvm_async_pf_enabled));
pa = slow_virt_to_phys(this_cpu_ptr(&apf_reason));
pa |= KVM_ASYNC_PF_ENABLED;
pa |= KVM_ASYNC_PF_ENABLED | KVM_ASYNC_PF_DELIVERY_AS_INT;
if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF_VMEXIT))
pa |= KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT;
wrmsrl(MSR_KVM_ASYNC_PF_INT, HYPERVISOR_CALLBACK_VECTOR);
wrmsrl(MSR_KVM_ASYNC_PF_EN, pa);
__this_cpu_write(apf_reason.enabled, 1);
pr_info("KVM setup async PF for cpu %d\n", smp_processor_id());
@ -643,8 +659,10 @@ static void __init kvm_guest_init(void)
if (kvm_para_has_feature(KVM_FEATURE_PV_EOI))
apic_set_eoi_write(kvm_guest_apic_eoi_write);
if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF) && kvmapf)
if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF_INT) && kvmapf) {
static_branch_enable(&kvm_async_pf_enabled);
alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, kvm_async_pf_vector);
}
#ifdef CONFIG_SMP
smp_ops.smp_prepare_cpus = kvm_smp_prepare_cpus;