No need to duplicate code, we now have the same path on all
architectures.
Additionally, suspend_cpu() is only called in hypervisor/control.c.
Restrict its visibility and make it static.
Signed-off-by: Ralf Ramsauer <ralf.ramsa...@oth-regensburg.de>
---
.../articles/LWN.net-article-01-2014.txt | 4 +-
hypervisor/arch/arm-common/control.c | 42 +------------
hypervisor/arch/x86/control.c | 42 +------------
hypervisor/control.c | 62 ++++++++++++++++++-
hypervisor/include/jailhouse/control.h | 29 ++-------
5 files changed, 70 insertions(+), 109 deletions(-)
diff --git a/Documentation/articles/LWN.net-article-01-2014.txt
b/Documentation/articles/LWN.net-article-01-2014.txt
index 07d0189b..bb958483 100644
--- a/Documentation/articles/LWN.net-article-01-2014.txt
+++ b/Documentation/articles/LWN.net-article-01-2014.txt
@@ -120,9 +120,9 @@ The main reason behind Jailhouse trapping ICR (and few
other registers) access i
Now let's turn to interrupt handling. In vmcs_setup(), Jailhouse skips
enabling external-interrupt exiting and sets exception bitmaps to all-zeroes.
This means the the only interrupt that results in VM exit is Non-Maskable
Interrupt (NMI). Everything else is dispatched through guest IDT and handled in
guest mode. Since cells asserts full control on their own resources, this
makes sense.
-Currently, NMIs can only come from the hypervisor itself (see TODO in
apic_deliver_ipi() function) which uses them to control CPUs
(arch_suspend_cpu() is an example). When NMI occurs in VM, it exits and
Jailhouse re-throws NMI in host mode. The CPU dispatches it through the host
IDT and jumps to apic_nmi_handler(). It schedules another VM exit using VMX
feature known as preemption timer. vmcs_setup() sets this timer to zero, so if
it is enabled, VM exit occurs immediately after VM entry. The reason behind
this indirection is serialization: this way, NMIs (which are asynchronous by
nature) are always delivered after guest entries.
+Currently, NMIs can only come from the hypervisor itself (see TODO in
apic_deliver_ipi() function) which uses them to control CPUs (suspend_cpu() is
an example). When NMI occurs in VM, it exits and Jailhouse re-throws NMI in
host mode. The CPU dispatches it through the host IDT and jumps to
apic_nmi_handler(). It schedules another VM exit using VMX feature known as
preemption timer. vmcs_setup() sets this timer to zero, so if it is enabled, VM
exit occurs immediately after VM entry. The reason behind this indirection is
serialization: this way, NMIs (which are asynchronous by nature) are always
delivered after guest entries.
-At this next exit, vmx_handle_exit() calls apic_handle_events() which spins in
a loop waiting for cpu_data->wait_for_sipi or cpu->stop_cpu to become false.
arch_suspend_cpu() sets cpu->stop_cpu flag and arch_resume_cpu() clears it, and
apic_deliver_ipi() function resets cpu_data->wait_for_sipi for a target CPU
when delivering Startup IPI (SIPI). It also stores the vector SIPI contains in
cpu_data->sipi_vector for later use (see "Creating a cell"). For
Jailhouse-initiated CPU resets, arch_reset_cpu() sets sipi_vector to
APIC_BSP_PSEUDO_SIPI (0x100, real SIPI vectors are always less than 0xff).
+At this next exit, vmx_handle_exit() calls apic_handle_events() which spins in
a loop waiting for cpu_data->wait_for_sipi or cpu->stop_cpu to become false.
suspend_cpu() sets cpu->stop_cpu flag and resume_cpu() clears it, and
apic_deliver_ipi() function resets cpu_data->wait_for_sipi for a target CPU
when delivering Startup IPI (SIPI). It also stores the vector SIPI contains in
cpu_data->sipi_vector for later use (see "Creating a cell"). For
Jailhouse-initiated CPU resets, arch_reset_cpu() sets sipi_vector to
APIC_BSP_PSEUDO_SIPI (0x100, real SIPI vectors are always less than 0xff).
Any other interrupt or exception in host mode is considered serious fault and
results in panic.
diff --git a/hypervisor/arch/arm-common/control.c
b/hypervisor/arch/arm-common/control.c
index 22101e83..b59c05d6 100644
--- a/hypervisor/arch/arm-common/control.c
+++ b/hypervisor/arch/arm-common/control.c
@@ -46,56 +46,18 @@ void arm_cpu_kick(unsigned int cpu_id)
irqchip_send_sgi(&sgi);
}
-void arch_suspend_cpu(unsigned int cpu_id)
-{
- struct public_per_cpu *target_data = public_per_cpu(cpu_id);
- bool target_suspended;
-
- spin_lock(&target_data->control_lock);
-
- target_data->suspend_cpu = true;
- target_suspended = target_data->cpu_suspended;
-
- spin_unlock(&target_data->control_lock);
-
- if (!target_suspended) {
- /*
- * Send a maintenance signal (SGI_EVENT) to the target CPU.
- * Then, wait for the target CPU to enter the suspended state.
- * The target CPU, in turn, will leave the guest and handle the
- * request in the event loop.
- */
- arch_send_event(target_data);
-
- while (!target_data->cpu_suspended)
- cpu_relax();
- }
-}
-
-void arch_resume_cpu(unsigned int cpu_id)
-{
- struct public_per_cpu *target_data = public_per_cpu(cpu_id);
-
- /* take lock to avoid theoretical race with a pending suspension */
- spin_lock(&target_data->control_lock);
-
- target_data->suspend_cpu = false;
-
- spin_unlock(&target_data->control_lock);
-}
-
void arch_reset_cpu(unsigned int cpu_id)
{
public_per_cpu(cpu_id)->reset = true;
- arch_resume_cpu(cpu_id);
+ resume_cpu(cpu_id);
}
void arch_park_cpu(unsigned int cpu_id)
{
public_per_cpu(cpu_id)->park = true;
- arch_resume_cpu(cpu_id);
+ resume_cpu(cpu_id);
}
static void check_events(struct public_per_cpu *cpu_public)
diff --git a/hypervisor/arch/x86/control.c b/hypervisor/arch/x86/control.c
index 6b39eb9d..11e5aabd 100644
--- a/hypervisor/arch/x86/control.c
+++ b/hypervisor/arch/x86/control.c
@@ -119,56 +119,18 @@ void arch_prepare_shutdown(void)
iommu_prepare_shutdown();
}
-void arch_suspend_cpu(unsigned int cpu_id)
-{
- struct public_per_cpu *target_data = public_per_cpu(cpu_id);
- bool target_suspended;
-
- spin_lock(&target_data->control_lock);
-
- target_data->suspend_cpu = true;
- target_suspended = target_data->cpu_suspended;
-
- spin_unlock(&target_data->control_lock);
-
- if (!target_suspended) {
- /*
- * Send a maintenance signal (NMI) to the target CPU.
- * Then, wait for the target CPU to enter the suspended state.
- * The target CPU, in turn, will leave the guest and handle the
- * request in the event loop.
- */
- arch_send_event(target_data);
-
- while (!target_data->cpu_suspended)
- cpu_relax();
- }
-}
-
-void arch_resume_cpu(unsigned int cpu_id)
-{
- struct public_per_cpu *target_data = public_per_cpu(cpu_id);
-
- /* take lock to avoid theoretical race with a pending suspension */
- spin_lock(&target_data->control_lock);
-
- target_data->suspend_cpu = false;
-
- spin_unlock(&target_data->control_lock);
-}
-
void arch_reset_cpu(unsigned int cpu_id)
{
public_per_cpu(cpu_id)->sipi_vector = APIC_BSP_PSEUDO_SIPI;
- arch_resume_cpu(cpu_id);
+ resume_cpu(cpu_id);
}
void arch_park_cpu(unsigned int cpu_id)
{
public_per_cpu(cpu_id)->init_signaled = true;
- arch_resume_cpu(cpu_id);
+ resume_cpu(cpu_id);
}
void x86_send_init_sipi(unsigned int cpu_id, enum x86_init_sipi type,
diff --git a/hypervisor/control.c b/hypervisor/control.c
index 5c03d806..0290bea7 100644
--- a/hypervisor/control.c
+++ b/hypervisor/control.c
@@ -20,6 +20,7 @@
#include <jailhouse/unit.h>
#include <jailhouse/utils.h>
#include <asm/bitops.h>
+#include <asm/control.h>
#include <asm/spinlock.h>
enum msg_type {MSG_REQUEST, MSG_INFORMATION};
@@ -73,6 +74,63 @@ bool cpu_id_valid(unsigned long cpu_id)
test_bit(cpu_id, system_cpu_set));
}
+/**
+ * Suspend a remote CPU.
+ * @param cpu_id ID of the target CPU.
+ *
+ * Suspension means that the target CPU is no longer executing cell code or
+ * arbitrary hypervisor code. It may actively busy-wait in the hypervisor
+ * context, so the suspension time should be kept short.
+ *
+ * The function waits for the target CPU to enter suspended state.
+ *
+ * This service can be used to synchronize with other CPUs before performing
+ * management tasks.
+ *
+ * @note This function must not be invoked for the caller's CPU.
+ *
+ * @see resume_cpu
+ * @see arch_reset_cpu
+ * @see arch_park_cpu
+ */
+static void suspend_cpu(unsigned int cpu_id)
+{
+ struct public_per_cpu *target_data = public_per_cpu(cpu_id);
+ bool target_suspended;
+
+ spin_lock(&target_data->control_lock);
+
+ target_data->suspend_cpu = true;
+ target_suspended = target_data->cpu_suspended;
+
+ spin_unlock(&target_data->control_lock);
+
+ if (!target_suspended) {
+ /*
+ * Send a maintenance signal to the target CPU.
+ * Then, wait for the target CPU to enter the suspended state.
+ * The target CPU, in turn, will leave the guest and handle the
+ * request in the event loop.
+ */
+ arch_send_event(target_data);
+
+ while (!target_data->cpu_suspended)
+ cpu_relax();
+ }
+}
+
+void resume_cpu(unsigned int cpu_id)
+{
+ struct public_per_cpu *target_data = public_per_cpu(cpu_id);
+
+ /* take lock to avoid theoretical race with a pending suspension */
+ spin_lock(&target_data->control_lock);
+
+ target_data->suspend_cpu = false;
+
+ spin_unlock(&target_data->control_lock);
+}
+
/*
* Suspend all CPUs assigned to the cell except the one executing
* the function (if it is in the cell's CPU set) to prevent races.
@@ -82,7 +140,7 @@ static void cell_suspend(struct cell *cell)
unsigned int cpu;
for_each_cpu_except(cpu, cell->cpu_set, this_cpu_id())
- arch_suspend_cpu(cpu);
+ suspend_cpu(cpu);
}
static void cell_resume(struct cell *cell)
@@ -90,7 +148,7 @@ static void cell_resume(struct cell *cell)
unsigned int cpu;
for_each_cpu_except(cpu, cell->cpu_set, this_cpu_id())
- arch_resume_cpu(cpu);
+ resume_cpu(cpu);
}
/**
diff --git a/hypervisor/include/jailhouse/control.h
b/hypervisor/include/jailhouse/control.h
index 2e1e9381..72518f6a 100644
--- a/hypervisor/include/jailhouse/control.h
+++ b/hypervisor/include/jailhouse/control.h
@@ -130,36 +130,15 @@ void shutdown(void);
void __attribute__((noreturn)) panic_stop(void);
void panic_park(void);
-/**
- * Suspend a remote CPU.
- * @param cpu_id ID of the target CPU.
- *
- * Suspension means that the target CPU is no longer executing cell code or
- * arbitrary hypervisor code. It may actively busy-wait in the hypervisor
- * context, so the suspension time should be kept short.
- *
- * The function waits for the target CPU to enter suspended state.
- *
- * This service can be used to synchronize with other CPUs before performing
- * management tasks.
- *
- * @note This function must not be invoked for the caller's CPU.
- *
- * @see arch_resume_cpu
- * @see arch_reset_cpu
- * @see arch_park_cpu
- */
-void arch_suspend_cpu(unsigned int cpu_id);
-
/**
* Resume a suspended remote CPU.
* @param cpu_id ID of the target CPU.
*
* @note This function must not be invoked for the caller's CPU.
*
- * @see arch_suspend_cpu
+ * @see suspend_cpu
*/
-void arch_resume_cpu(unsigned int cpu_id);
+void resume_cpu(unsigned int cpu_id);
/**
* Reset a suspended remote CPU and resumes its execution.
@@ -171,7 +150,7 @@ void arch_resume_cpu(unsigned int cpu_id);
* @note This function must not be invoked for the caller's CPU or if the
* target CPU is not in suspend state.
*
- * @see arch_suspend_cpu
+ * @see suspend_cpu
*/
void arch_reset_cpu(unsigned int cpu_id);
@@ -190,7 +169,7 @@ void arch_reset_cpu(unsigned int cpu_id);
* @note This function must not be invoked for the caller's CPU or if the
* target CPU is not in suspend state.
*
- * @see arch_suspend_cpu
+ * @see suspend_cpu
*/
void arch_park_cpu(unsigned int cpu_id);
--
2.18.0
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