[RFC PATCH 61/73] x86/pvm: Allow to install a system interrupt handler

Lai Jiangshan
2024-02-26T14:38:49Z

From: Hou Wenlong <houwenlong.hwl@antgroup.com>

Add pvm_sysvec_install() to install a system interrupt handler into PVM
system interrupt handler table.

Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
---
arch/x86/include/asm/pvm_para.h | 6 ++++++
arch/x86/kernel/kvm.c | 2 ++
arch/x86/kernel/pvm.c | 11 +++++++++--
3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/pvm_para.h b/arch/x86/include/asm/pvm_para.h
index c344185a192c..9216e539fea8 100644
--- a/arch/x86/include/asm/pvm_para.h
+++ b/arch/x86/include/asm/pvm_para.h
@@ -6,12 +6,14 @@
#include <uapi/asm/pvm_para.h>

#ifndef __ASSEMBLY__
+typedef void (*idtentry_t)(struct pt_regs *regs);

#ifdef CONFIG_PVM_GUEST
#include <asm/irqflags.h>
#include <uapi/asm/kvm_para.h>

void __init pvm_early_setup(void);
+void __init pvm_install_sysvec(unsigned int sysvec, idtentry_t handler);
bool __init pvm_kernel_layout_relocate(void);

static inline void pvm_cpuid(unsigned int *eax, unsigned int *ebx,
@@ -68,6 +70,10 @@ static inline void pvm_early_setup(void)
{
}

+static inline void pvm_install_sysvec(unsigned int sysvec, idtentry_t handler)
+{
+}
+
static inline bool pvm_kernel_layout_relocate(void)
{
return false;
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index de72a5a1f7ad..87b00c279aaf 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -43,6 +43,7 @@
#include <asm/reboot.h>
#include <asm/svm.h>
#include <asm/e820/api.h>
+#include <asm/pvm_para.h>

DEFINE_STATIC_KEY_FALSE(kvm_async_pf_enabled);

@@ -843,6 +844,7 @@ static void __init kvm_guest_init(void)
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);
+ pvm_install_sysvec(HYPERVISOR_CALLBACK_VECTOR, sysvec_kvm_asyncpf_interrupt);
}

#ifdef CONFIG_SMP
diff --git a/arch/x86/kernel/pvm.c b/arch/x86/kernel/pvm.c
index 9399e45b3c13..88b013185ecd 100644
--- a/arch/x86/kernel/pvm.c
+++ b/arch/x86/kernel/pvm.c
@@ -128,8 +128,6 @@ static noinstr void pvm_handle_INT80_compat(struct pt_regs *regs)
exc_general_protection(regs, 0);
}

-typedef void (*idtentry_t)(struct pt_regs *regs);
-
#define SYSVEC(_vector, _function) [_vector - FIRST_SYSTEM_VECTOR] = sysvec_##_function

#define pvm_handle_spurious_interrupt ((idtentry_t)(void *)spurious_interrupt)
@@ -167,6 +165,15 @@ static idtentry_t pvm_sysvec_table[NR_SYSTEM_VECTORS] __ro_after_init = {
#endif
};

+void __init pvm_install_sysvec(unsigned int sysvec, idtentry_t handler)
+{
+ if (WARN_ON_ONCE(sysvec < FIRST_SYSTEM_VECTOR))
+ return;
+ if (!WARN_ON_ONCE(pvm_sysvec_table[sysvec - FIRST_SYSTEM_VECTOR] !=
+ pvm_handle_spurious_interrupt))
+ pvm_sysvec_table[sysvec - FIRST_SYSTEM_VECTOR] = handler;
+}
+
/*
* some pointers in pvm_sysvec_table are actual spurious_interrupt() who
* expects the second argument to be the vector.
--
2.19.1.6.gb485710b