| Message ID | 20230916003118.2540661-23-seanjc@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: vfio: Hide KVM internals from others | expand |
On Sat, Sep 16, 2023 at 6:02 AM Sean Christopherson <seanjc@google.com> wrote: > > Move KVM's morphing of pending signals into exits to userspace 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 removing the non-KVM call to kvm_handle_signal_exit() will allow > hiding said API and the definition of "struct kvm_vcpu" from the kernel. > > Alternatively, entry/kvm.c could be treated as part of KVM, i.e. be given > access to KVM internals, but that's not obviously better than having KVM > react to -EINTR (though it's not obviously worse either). > > Signed-off-by: Sean Christopherson <seanjc@google.com> For KVM RISC-V: Anup Patel <anup@brainfault.org> Regards, Anup > --- > arch/arm64/kvm/arm.c | 3 +-- > arch/riscv/kvm/vcpu.c | 2 +- > arch/x86/kvm/vmx/vmx.c | 1 - > arch/x86/kvm/x86.c | 3 +-- > include/linux/entry-kvm.h | 3 +-- > include/linux/kvm_host.h | 13 ++++++++++++- > kernel/entry/kvm.c | 11 ++++------- > 7 files changed, 20 insertions(+), 16 deletions(-) > > diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c > index 6480628197b4..641df091e46b 100644 > --- 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> > @@ -929,7 +928,7 @@ 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/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c > index 82229db1ce73..c313f4e90e70 100644 > --- a/arch/riscv/kvm/vcpu.c > +++ b/arch/riscv/kvm/vcpu.c > @@ -667,7 +667,7 @@ 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 faf0071566ef..43b87ad5fde8 100644 > --- 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 6c9c81e82e65..aab095f89d9e 100644 > --- 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> > > @@ -10987,7 +10986,7 @@ 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 e7d90d06e566..e235a91d28fc 100644 > --- a/include/linux/entry-kvm.h > +++ b/include/linux/entry-kvm.h > @@ -42,11 +42,10 @@ static inline int arch_xfer_to_guest_mode_handle_work(unsigned long ti_work) > /** > * 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 fb6c6109fdca..d520d6801070 100644 > --- 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> > @@ -2293,6 +2293,17 @@ 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 c2fc39824157..872617468b4a 100644 > --- 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) > schedule(); > @@ -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); > -- > 2.42.0.459.ge4e396fd5e-goog >
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 6480628197b4..641df091e46b 100644 --- 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> @@ -929,7 +928,7 @@ 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/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c index 82229db1ce73..c313f4e90e70 100644 --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -667,7 +667,7 @@ 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 faf0071566ef..43b87ad5fde8 100644 --- 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 6c9c81e82e65..aab095f89d9e 100644 --- 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> @@ -10987,7 +10986,7 @@ 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 e7d90d06e566..e235a91d28fc 100644 --- a/include/linux/entry-kvm.h +++ b/include/linux/entry-kvm.h @@ -42,11 +42,10 @@ static inline int arch_xfer_to_guest_mode_handle_work(unsigned long ti_work) /** * 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 fb6c6109fdca..d520d6801070 100644 --- 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> @@ -2293,6 +2293,17 @@ 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 c2fc39824157..872617468b4a 100644 --- 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) schedule(); @@ -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);
Move KVM's morphing of pending signals into exits to userspace 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 removing the non-KVM call to kvm_handle_signal_exit() will allow hiding said API and the definition of "struct kvm_vcpu" from the kernel. Alternatively, entry/kvm.c could be treated as part of KVM, i.e. be given access to KVM internals, but that's not obviously better than having KVM react to -EINTR (though it's not obviously worse either). Signed-off-by: Sean Christopherson <seanjc@google.com> --- arch/arm64/kvm/arm.c | 3 +-- arch/riscv/kvm/vcpu.c | 2 +- arch/x86/kvm/vmx/vmx.c | 1 - arch/x86/kvm/x86.c | 3 +-- include/linux/entry-kvm.h | 3 +-- include/linux/kvm_host.h | 13 ++++++++++++- kernel/entry/kvm.c | 11 ++++------- 7 files changed, 20 insertions(+), 16 deletions(-)