[RFC PATCH v2 2/3] arch/x86/acrn: Use HYPERVISOR_CALLBACK_VECTOR for Acrn upcall vector

From: Zhao Yakui
Date: Tue Mar 26 2019 - 00:55:15 EST


Linux kernel uses the HYPERVISOR_CALLBACK_VECTOR for hypervisor upcall
vector. And it is already used for Xen and HyperV.
After Acrn hypervisor is detected, it will also use this defined vector
to notify kernel.

V1->V2: Remove the unused API definition of acrn_setup_intr_handler and
acrn_remove_intr_handler.
Adjust the order of header file
Add the declaration of acrn_hv_vector_handler and tracing
definition of acrn_hv_callback_vector.

Co-developed-by: Jason Chen CJ <jason.cj.chen@xxxxxxxxx>
Signed-off-by: Jason Chen CJ <jason.cj.chen@xxxxxxxxx>
Signed-off-by: Zhao Yakui <yakui.zhao@xxxxxxxxx>
---
arch/x86/entry/entry_64.S | 5 +++++
arch/x86/include/asm/acrnhyper.h | 19 +++++++++++++++++++
arch/x86/include/asm/hardirq.h | 3 ++-
arch/x86/kernel/cpu/acrn.c | 22 ++++++++++++++++++++++
arch/x86/kernel/irq.c | 3 ++-
5 files changed, 50 insertions(+), 2 deletions(-)
create mode 100644 arch/x86/include/asm/acrnhyper.h

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 1f0efdb..d1b8ad3 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1129,6 +1129,11 @@ apicinterrupt3 HYPERV_STIMER0_VECTOR \
hv_stimer0_callback_vector hv_stimer0_vector_handler
#endif /* CONFIG_HYPERV */

+#if IS_ENABLED(CONFIG_ACRN_GUEST)
+apicinterrupt3 HYPERVISOR_CALLBACK_VECTOR \
+ acrn_hv_callback_vector acrn_hv_vector_handler
+#endif
+
idtentry debug do_debug has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK
idtentry int3 do_int3 has_error_code=0
idtentry stack_segment do_stack_segment has_error_code=1
diff --git a/arch/x86/include/asm/acrnhyper.h b/arch/x86/include/asm/acrnhyper.h
new file mode 100644
index 0000000..9f9c239
--- /dev/null
+++ b/arch/x86/include/asm/acrnhyper.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_ACRNHYPER_H
+#define _ASM_X86_ACRNHYPER_H
+
+#include <linux/types.h>
+#include <linux/atomic.h>
+#include <linux/nmi.h>
+#include <asm/io.h>
+
+#ifdef CONFIG_ACRN_GUEST
+void acrn_hv_callback_vector(void);
+#ifdef CONFIG_TRACING
+#define trace_acrn_hv_callback_vector acrn_hv_callback_vector
+#endif
+
+void acrn_hv_vector_handler(struct pt_regs *regs);
+#endif
+
+#endif
diff --git a/arch/x86/include/asm/hardirq.h b/arch/x86/include/asm/hardirq.h
index d9069bb..a8f4d08 100644
--- a/arch/x86/include/asm/hardirq.h
+++ b/arch/x86/include/asm/hardirq.h
@@ -37,7 +37,8 @@ typedef struct {
#ifdef CONFIG_X86_MCE_AMD
unsigned int irq_deferred_error_count;
#endif
-#if IS_ENABLED(CONFIG_HYPERV) || defined(CONFIG_XEN)
+#if IS_ENABLED(CONFIG_HYPERV) || defined(CONFIG_XEN) ||\
+ defined(CONFIG_ACRN_GUEST)
unsigned int irq_hv_callback_count;
#endif
#if IS_ENABLED(CONFIG_HYPERV)
diff --git a/arch/x86/kernel/cpu/acrn.c b/arch/x86/kernel/cpu/acrn.c
index 3956567..7a233b5 100644
--- a/arch/x86/kernel/cpu/acrn.c
+++ b/arch/x86/kernel/cpu/acrn.c
@@ -9,7 +9,11 @@
*
*/

+#include <linux/interrupt.h>
#include <asm/hypervisor.h>
+#include <asm/acrnhyper.h>
+#include <asm/desc.h>
+#include <asm/irq_regs.h>

static uint32_t __init acrn_detect(void)
{
@@ -18,6 +22,8 @@ static uint32_t __init acrn_detect(void)

static void __init acrn_init_platform(void)
{
+ alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,
+ acrn_hv_callback_vector);
}

static bool acrn_x2apic_available(void)
@@ -26,6 +32,22 @@ static bool acrn_x2apic_available(void)
return false;
}

+static void (*acrn_intr_handler)(void);
+
+__visible void __irq_entry acrn_hv_vector_handler(struct pt_regs *regs)
+{
+ struct pt_regs *old_regs = set_irq_regs(regs);
+
+ entering_ack_irq();
+ inc_irq_stat(irq_hv_callback_count);
+
+ if (acrn_intr_handler)
+ acrn_intr_handler();
+
+ exiting_irq();
+ set_irq_regs(old_regs);
+}
+
const __initconst struct hypervisor_x86 x86_hyper_acrn = {
.name = "ACRN",
.detect = acrn_detect,
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 59b5f2e..02c6ff6 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -134,7 +134,8 @@ int arch_show_interrupts(struct seq_file *p, int prec)
seq_printf(p, "%10u ", per_cpu(mce_poll_count, j));
seq_puts(p, " Machine check polls\n");
#endif
-#if IS_ENABLED(CONFIG_HYPERV) || defined(CONFIG_XEN)
+#if IS_ENABLED(CONFIG_HYPERV) || defined(CONFIG_XEN) ||\
+ defined(CONFIG_ACRN_GUEST)
if (test_bit(HYPERVISOR_CALLBACK_VECTOR, system_vectors)) {
seq_printf(p, "%*s: ", prec, "HYP");
for_each_online_cpu(j)
--
2.7.4