From 2f529f9b558ca1c1bd74be7437a84e4711743404 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 01 Nov 2024 02:11:33 +0000
Subject: [PATCH] add xenomai
---
kernel/arch/x86/kvm/x86.c | 106 ++++++++++++++++++++++++++++++++++++++++++++---------
1 files changed, 88 insertions(+), 18 deletions(-)
diff --git a/kernel/arch/x86/kvm/x86.c b/kernel/arch/x86/kvm/x86.c
index 23d7c56..7928751 100644
--- a/kernel/arch/x86/kvm/x86.c
+++ b/kernel/arch/x86/kvm/x86.c
@@ -178,6 +178,7 @@
struct kvm_user_return_msrs {
struct user_return_notifier urn;
bool registered;
+ bool dirty;
struct kvm_user_return_msr_values {
u64 host;
u64 curr;
@@ -295,12 +296,29 @@
vcpu->arch.apf.gfns[i] = ~0;
}
+static void __kvm_on_user_return(struct kvm_user_return_msrs *msrs)
+{
+ struct kvm_user_return_msr_values *values;
+ unsigned slot;
+
+ if (!msrs->dirty)
+ return;
+
+ for (slot = 0; slot < user_return_msrs_global.nr; ++slot) {
+ values = &msrs->values[slot];
+ if (values->host != values->curr) {
+ wrmsrl(user_return_msrs_global.msrs[slot], values->host);
+ values->curr = values->host;
+ }
+ }
+
+ msrs->dirty = false;
+}
+
static void kvm_on_user_return(struct user_return_notifier *urn)
{
- unsigned slot;
struct kvm_user_return_msrs *msrs
= container_of(urn, struct kvm_user_return_msrs, urn);
- struct kvm_user_return_msr_values *values;
unsigned long flags;
/*
@@ -313,13 +331,10 @@
user_return_notifier_unregister(urn);
}
local_irq_restore(flags);
- for (slot = 0; slot < user_return_msrs_global.nr; ++slot) {
- values = &msrs->values[slot];
- if (values->host != values->curr) {
- wrmsrl(user_return_msrs_global.msrs[slot], values->host);
- values->curr = values->host;
- }
- }
+ flags = hard_cond_local_irq_save();
+ __kvm_on_user_return(msrs);
+ hard_cond_local_irq_restore(flags);
+ inband_exit_guest();
}
int kvm_probe_user_return_msr(u32 msr)
@@ -374,6 +389,7 @@
if (err)
return 1;
+ msrs->dirty = true;
msrs->values[slot].curr = value;
if (!msrs->registered) {
msrs->urn.on_user_return = kvm_on_user_return;
@@ -4072,10 +4088,22 @@
void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
{
+ struct kvm_user_return_msrs *msrs = this_cpu_ptr(user_return_msrs);
+ unsigned long flags;
int idx;
if (vcpu->preempted)
vcpu->arch.preempted_in_kernel = !kvm_x86_ops.get_cpl(vcpu);
+
+ flags = hard_cond_local_irq_save();
+ /*
+ * Skip steal time accounting from the out-of-band stage since
+ * this is oob-unsafe. We leave it to the next call from the
+ * inband stage.
+ */
+ if (running_oob())
+ goto skip_steal_time_update;
+
/*
* Disable page faults because we're in atomic context here.
@@ -4094,6 +4122,7 @@
kvm_steal_time_set_preempted(vcpu);
srcu_read_unlock(&vcpu->kvm->srcu, idx);
pagefault_enable();
+skip_steal_time_update:
kvm_x86_ops.vcpu_put(vcpu);
vcpu->arch.last_host_tsc = rdtsc();
/*
@@ -4102,7 +4131,40 @@
* guest. do_debug expects dr6 to be cleared after it runs, do the same.
*/
set_debugreg(0, 6);
+
+ inband_set_vcpu_release_state(vcpu, false);
+ if (!msrs->dirty)
+ inband_exit_guest();
+
+ hard_cond_local_irq_restore(flags);
}
+
+#ifdef CONFIG_DOVETAIL
+/* hard irqs off. */
+void kvm_handle_oob_switch(struct kvm_oob_notifier *nfy)
+{
+ struct kvm_user_return_msrs *msrs = this_cpu_ptr(user_return_msrs);
+ struct kvm_vcpu *vcpu;
+
+ vcpu = container_of(nfy, struct kvm_vcpu, oob_notifier);
+ /*
+ * If user_return MSRs were still active when leaving
+ * kvm_arch_vcpu_put(), inband_exit_guest() was not invoked,
+ * so we might get called later on before kvm_on_user_return()
+ * had a chance to run, if a switch to out-of-band scheduling
+ * sneaks in in the meantime. Prevent kvm_arch_vcpu_put()
+ * from running twice in such a case by checking ->put_vcpu
+ * from the notifier block.
+ */
+ if (nfy->put_vcpu)
+ kvm_arch_vcpu_put(vcpu);
+
+ __kvm_on_user_return(msrs);
+ inband_exit_guest();
+}
+#else
+#define kvm_handle_oob_switch NULL
+#endif
static int kvm_vcpu_ioctl_get_lapic(struct kvm_vcpu *vcpu,
struct kvm_lapic_state *s)
@@ -9142,6 +9204,10 @@
}
preempt_disable();
+ local_irq_disable_full();
+
+ inband_enter_guest(vcpu);
+ inband_set_vcpu_release_state(vcpu, true);
kvm_x86_ops.prepare_guest_switch(vcpu);
@@ -9150,7 +9216,6 @@
* IPI are then delayed after guest entry, which ensures that they
* result in virtual interrupt delivery.
*/
- local_irq_disable();
vcpu->mode = IN_GUEST_MODE;
srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
@@ -9179,7 +9244,7 @@
if (kvm_vcpu_exit_request(vcpu)) {
vcpu->mode = OUTSIDE_GUEST_MODE;
smp_wmb();
- local_irq_enable();
+ local_irq_enable_full();
preempt_enable();
vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
r = 1;
@@ -9251,9 +9316,9 @@
* stat.exits increment will do nicely.
*/
kvm_before_interrupt(vcpu);
- local_irq_enable();
+ local_irq_enable_full();
++vcpu->stat.exits;
- local_irq_disable();
+ local_irq_disable_full();
kvm_after_interrupt(vcpu);
/*
@@ -9273,7 +9338,7 @@
}
}
- local_irq_enable();
+ local_irq_enable_full();
preempt_enable();
vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
@@ -9487,7 +9552,9 @@
/* Swap (qemu) user FPU context for the guest FPU context. */
static void kvm_load_guest_fpu(struct kvm_vcpu *vcpu)
{
- fpregs_lock();
+ unsigned long flags;
+
+ flags = fpregs_lock();
kvm_save_current_fpu(vcpu->arch.user_fpu);
@@ -9496,7 +9563,7 @@
~XFEATURE_MASK_PKRU);
fpregs_mark_activate();
- fpregs_unlock();
+ fpregs_unlock(flags);
trace_kvm_fpu(1);
}
@@ -9504,14 +9571,16 @@
/* When vcpu_run ends, restore user space FPU context. */
static void kvm_put_guest_fpu(struct kvm_vcpu *vcpu)
{
- fpregs_lock();
+ unsigned long flags;
+
+ flags = fpregs_lock();
kvm_save_current_fpu(vcpu->arch.guest_fpu);
copy_kernel_to_fpregs(&vcpu->arch.user_fpu->state);
fpregs_mark_activate();
- fpregs_unlock();
+ fpregs_unlock(flags);
++vcpu->stat.fpu_reload;
trace_kvm_fpu(0);
@@ -10189,6 +10258,7 @@
if (r)
goto free_guest_fpu;
+ inband_init_vcpu(vcpu, kvm_handle_oob_switch);
vcpu->arch.arch_capabilities = kvm_get_arch_capabilities();
vcpu->arch.msr_platform_info = MSR_PLATFORM_INFO_CPUID_FAULT;
kvm_vcpu_mtrr_init(vcpu);
--
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