entry/kvm: KVM: Move KVM details related to signal/-EINTR into KVM proper

Move KVM's morphing of pending signals into userspace exits into KVM
proper, and drop the @vcpu param from xfer_to_guest_mode_handle_work().
How KVM responds to -EINTR is a detail that really belongs in KVM itself,
and invoking kvm_handle_signal_exit() from kernel code creates an inverted
module dependency.  E.g. attempting to move kvm_handle_signal_exit() into
kvm_main.c would generate an linker error when building kvm.ko as a module.

Dropping KVM details will also converting the KVM "entry" code into a more
generic virtualization framework so that it can be used when running as a
Hyper-V root partition.

Lastly, eliminating usage of "struct kvm_vcpu" outside of KVM is also nice
to have for KVM x86 developers, as keeping the details of kvm_vcpu purely
within KVM allows changing the layout of the structure without having to
boot into a new kernel, e.g. allows rebuilding and reloading kvm.ko with a
modified kvm_vcpu structure as part of debug/development.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 888f7c7abf547a011331082a23f5799b1f6fab73..418fd3043467e657971aa6b0bc23b8d465ecfb2e 100644 (file)
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -6,7 +6,6 @@
 
 #include <linux/bug.h>
 #include <linux/cpu_pm.h>
-#include <linux/entry-kvm.h>
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/kvm_host.h>
@@ -1177,7 +1176,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
                /*
                 * Check conditions before entering the guest
                 */
-               ret = xfer_to_guest_mode_handle_work(vcpu);
+               ret = kvm_xfer_to_guest_mode_handle_work(vcpu);
                if (!ret)
                        ret = 1;
 

diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c
index d1b8c50941ca233a8fc4519a8276d6bccd916f24..514256b25ba140c6c321b9ea93c54b7093e424f4 100644 (file)
--- a/arch/loongarch/kvm/vcpu.c
+++ b/arch/loongarch/kvm/vcpu.c
@@ -4,7 +4,6 @@
  */
 
 #include <linux/kvm_host.h>
-#include <linux/entry-kvm.h>
 #include <asm/fpu.h>
 #include <asm/lbt.h>
 #include <asm/loongarch.h>
@@ -251,7 +250,7 @@ static int kvm_enter_guest_check(struct kvm_vcpu *vcpu)
        /*
         * Check conditions before entering the guest
         */
-       ret = xfer_to_guest_mode_handle_work(vcpu);
+       ret = kvm_xfer_to_guest_mode_handle_work(vcpu);
        if (ret < 0)
                return ret;
 

diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index f001e56403f9fa9aeb54cec06ee7631a49401d7d..251e787f2ebcedbdd15cb55a9237b53500f87ddf 100644 (file)
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -7,7 +7,6 @@
  */
 
 #include <linux/bitops.h>
-#include <linux/entry-kvm.h>
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/kdebug.h>
@@ -910,7 +909,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
        run->exit_reason = KVM_EXIT_UNKNOWN;
        while (ret > 0) {
                /* Check conditions before entering the guest */
-               ret = xfer_to_guest_mode_handle_work(vcpu);
+               ret = kvm_xfer_to_guest_mode_handle_work(vcpu);
                if (ret)
                        continue;
                ret = 1;

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index aa157fe5b7b31802aa71351db92c8d1b68111432..d7c86613e50af40f4f65e5e1162df0872391b39a 100644 (file)
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -28,7 +28,6 @@
 #include <linux/slab.h>
 #include <linux/tboot.h>
 #include <linux/trace_events.h>
-#include <linux/entry-kvm.h>
 
 #include <asm/apic.h>
 #include <asm/asm.h>

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a1c49bc681c46995986c347a09b5e79fb5b874d6..0b13b8bf69e5ce7c8c855857c3f813c9bf3d5547 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -59,7 +59,6 @@
 #include <linux/sched/stat.h>
 #include <linux/sched/isolation.h>
 #include <linux/mem_encrypt.h>
-#include <linux/entry-kvm.h>
 #include <linux/suspend.h>
 #include <linux/smp.h>
 
@@ -11241,7 +11240,7 @@ static int vcpu_run(struct kvm_vcpu *vcpu)
 
                if (__xfer_to_guest_mode_work_pending()) {
                        kvm_vcpu_srcu_read_unlock(vcpu);
-                       r = xfer_to_guest_mode_handle_work(vcpu);
+                       r = kvm_xfer_to_guest_mode_handle_work(vcpu);
                        kvm_vcpu_srcu_read_lock(vcpu);
                        if (r)
                                return r;

diff --git a/include/linux/entry-kvm.h b/include/linux/entry-kvm.h
index 16149f6625e48a3ff3f32aa4fabac3aba374c103..3644de7e601960d582544eeb366fa70112511d3c 100644 (file)
--- a/include/linux/entry-kvm.h
+++ b/include/linux/entry-kvm.h
@@ -21,8 +21,6 @@
         _TIF_NOTIFY_SIGNAL | _TIF_NOTIFY_RESUME |                      \
         ARCH_XFER_TO_GUEST_MODE_WORK)
 
-struct kvm_vcpu;
-
 /**
  * arch_xfer_to_guest_mode_handle_work - Architecture specific xfer to guest
  *                                      mode work handling function.
@@ -32,12 +30,10 @@ struct kvm_vcpu;
  * Invoked from xfer_to_guest_mode_handle_work(). Defaults to NOOP. Can be
  * replaced by architecture specific code.
  */
-static inline int arch_xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu,
-                                                     unsigned long ti_work);
+static inline int arch_xfer_to_guest_mode_handle_work(unsigned long ti_work);
 
 #ifndef arch_xfer_to_guest_mode_work
-static inline int arch_xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu,
-                                                     unsigned long ti_work)
+static inline int arch_xfer_to_guest_mode_handle_work(unsigned long ti_work)
 {
        return 0;
 }
@@ -46,11 +42,10 @@ static inline int arch_xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu,
 /**
  * xfer_to_guest_mode_handle_work - Check and handle pending work which needs
  *                                 to be handled before going to guest mode
- * @vcpu:      Pointer to current's VCPU data
  *
  * Returns: 0 or an error code
  */
-int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu);
+int xfer_to_guest_mode_handle_work(void);
 
 /**
  * xfer_to_guest_mode_prepare - Perform last minute preparation work that

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 15656b7fba6c7f85f6723ef1f54b66a6fc0e90cb..598b9473e46d6ccd798842ee73a9069ae4efa5c4 100644 (file)
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -2,7 +2,7 @@
 #ifndef __KVM_HOST_H
 #define __KVM_HOST_H
 
-
+#include <linux/entry-kvm.h>
 #include <linux/types.h>
 #include <linux/hardirq.h>
 #include <linux/list.h>
@@ -2450,6 +2450,17 @@ static inline void kvm_handle_signal_exit(struct kvm_vcpu *vcpu)
        vcpu->run->exit_reason = KVM_EXIT_INTR;
        vcpu->stat.signal_exits++;
 }
+
+static inline int kvm_xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu)
+{
+       int r = xfer_to_guest_mode_handle_work();
+
+       if (r) {
+               WARN_ON_ONCE(r != -EINTR);
+               kvm_handle_signal_exit(vcpu);
+       }
+       return r;
+}
 #endif /* CONFIG_KVM_XFER_TO_GUEST_WORK */
 
 /*

diff --git a/kernel/entry/kvm.c b/kernel/entry/kvm.c
index 8485f63863afcc413f39f117e4d157b50f03d179..6fc762eaacca7cb173b5dfcf9c067474a7a929c0 100644 (file)
--- a/kernel/entry/kvm.c
+++ b/kernel/entry/kvm.c
@@ -1,17 +1,14 @@
 // SPDX-License-Identifier: GPL-2.0
 
 #include <linux/entry-kvm.h>
-#include <linux/kvm_host.h>
 
-static int xfer_to_guest_mode_work(struct kvm_vcpu *vcpu, unsigned long ti_work)
+static int xfer_to_guest_mode_work(unsigned long ti_work)
 {
        do {
                int ret;
 
-               if (ti_work & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) {
-                       kvm_handle_signal_exit(vcpu);
+               if (ti_work & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
                        return -EINTR;
-               }
 
                if (ti_work & (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY))
                        schedule();
@@ -19,7 +16,7 @@ static int xfer_to_guest_mode_work(struct kvm_vcpu *vcpu, unsigned long ti_work)
                if (ti_work & _TIF_NOTIFY_RESUME)
                        resume_user_mode_work(NULL);
 
-               ret = arch_xfer_to_guest_mode_handle_work(vcpu, ti_work);
+               ret = arch_xfer_to_guest_mode_handle_work(ti_work);
                if (ret)
                        return ret;
 
@@ -28,7 +25,7 @@ static int xfer_to_guest_mode_work(struct kvm_vcpu *vcpu, unsigned long ti_work)
        return 0;
 }
 
-int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu)
+int xfer_to_guest_mode_handle_work(void)
 {
        unsigned long ti_work;
 
@@ -44,6 +41,6 @@ int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu)
        if (!(ti_work & XFER_TO_GUEST_MODE_WORK))
                return 0;
 
-       return xfer_to_guest_mode_work(vcpu, ti_work);
+       return xfer_to_guest_mode_work(ti_work);
 }
 EXPORT_SYMBOL_GPL(xfer_to_guest_mode_handle_work);