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Merge branch 'kvm-async-pf-int' into HEAD

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This commit is contained in:
Paolo Bonzini 2020-06-15 07:53:05 -04:00
commit 26d05b368a
4 changed files with 40 additions and 13 deletions
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1
arch/x86/Kconfig
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@ -802,6 +802,7 @@ 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

4
arch/x86/include/asm/idtentry.h
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@ -647,6 +647,10 @@ DECLARE_IDTENTRY_SYSVEC(HYPERVISOR_CALLBACK_VECTOR, sysvec_acrn_hv_callback);
DECLARE_IDTENTRY_SYSVEC(HYPERVISOR_CALLBACK_VECTOR, sysvec_xen_hvm_callback);
#endif
#ifdef CONFIG_KVM_GUEST
DECLARE_IDTENTRY_SYSVEC(HYPERVISOR_CALLBACK_VECTOR, sysvec_kvm_asyncpf_interrupt);
#endif
#undef X86_TRAP_OTHER
#endif

1
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);

47
arch/x86/kernel/kvm.c
View File

@ -9,6 +9,7 @@
#include <linux/context_tracking.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/kvm_para.h>
#include <linux/cpu.h>
@ -232,16 +233,11 @@ EXPORT_SYMBOL_GPL(kvm_read_and_reset_apf_flags);
noinstr 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();
bool rcu_exit;
switch (reason) {
case KVM_PV_REASON_PAGE_NOT_PRESENT:
case KVM_PV_REASON_PAGE_READY:
break;
default:
if (!flags)
return false;
}
rcu_exit = idtentry_enter_cond_rcu(regs);
instrumentation_begin();
@ -254,13 +250,13 @@ noinstr 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 {
kvm_async_pf_task_wake(token);
WARN_ONCE(1, "Unexpected async PF flags: %x\n", flags);
}
instrumentation_end();
@ -268,6 +264,27 @@ noinstr bool __kvm_handle_async_pf(struct pt_regs *regs, u32 token)
return true;
}
DEFINE_IDTENTRY_SYSVEC(sysvec_kvm_asyncpf_interrupt)
{
struct pt_regs *old_regs = set_irq_regs(regs);
u32 token;
bool rcu_exit;
rcu_exit = idtentry_enter_cond_rcu(regs);
inc_irq_stat(irq_hv_callback_count);
if (__this_cpu_read(apf_reason.enabled)) {
token = __this_cpu_read(apf_reason.token);
kvm_async_pf_task_wake(token);
__this_cpu_write(apf_reason.token, 0);
wrmsrl(MSR_KVM_ASYNC_PF_ACK, 1);
}
idtentry_exit_cond_rcu(regs, rcu_exit);
set_irq_regs(old_regs);
}
static void __init paravirt_ops_setup(void)
{
pv_info.name = "KVM";
@ -311,17 +328,19 @@ 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());
@ -646,8 +665,10 @@ 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, asm_sysvec_kvm_asyncpf_interrupt);
}
#ifdef CONFIG_SMP
smp_ops.smp_prepare_cpus = kvm_smp_prepare_cpus;