KVM: move vcpu locking to dispatcher for generic vcpu ioctls

All vcpu ioctls need to be locked, so instead of locking each one specifically
we lock at the generic dispatcher.

This patch only updates generic ioctls and leaves arch specific ioctls alone.

Signed-off-by: Avi Kivity <avi@redhat.com>

7 files changed, 17 insertions, 95 deletions

diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index 21b701374f7..91760e80e26 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -725,8 +725,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
         int r;
         sigset_t sigsaved;
 
-        vcpu_load(vcpu);
-
         if (vcpu->sigset_active)
                 sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);
 
@@ -748,7 +746,6 @@ out:
         if (vcpu->sigset_active)
                 sigprocmask(SIG_SETMASK, &sigsaved, NULL);
 
-        vcpu_put(vcpu);
         return r;
 }
 
@@ -883,8 +880,6 @@ int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
         struct vpd *vpd = to_host(vcpu->kvm, vcpu->arch.vpd);
         int i;
 
-        vcpu_load(vcpu);
-
         for (i = 0; i < 16; i++) {
                 vpd->vgr[i] = regs->vpd.vgr[i];
                 vpd->vbgr[i] = regs->vpd.vbgr[i];
@@ -931,8 +926,6 @@ int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
         vcpu->arch.itc_offset = regs->saved_itc - kvm_get_itc(vcpu);
         set_bit(KVM_REQ_RESUME, &vcpu->requests);
 
-        vcpu_put(vcpu);
-
         return 0;
 }
 
@@ -1967,9 +1960,7 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)
 int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
                                     struct kvm_mp_state *mp_state)
 {
-        vcpu_load(vcpu);
         mp_state->mp_state = vcpu->arch.mp_state;
-        vcpu_put(vcpu);
         return 0;
 }
 
@@ -2000,10 +1991,8 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
 {
         int r = 0;
 
-        vcpu_load(vcpu);
         vcpu->arch.mp_state = mp_state->mp_state;
         if (vcpu->arch.mp_state == KVM_MP_STATE_UNINITIALIZED)
                 r = vcpu_reset(vcpu);
-        vcpu_put(vcpu);
         return r;
 }
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index b998abf1a63..f6eac2f337d 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -1047,8 +1047,6 @@ int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 {
         int i;
 
-        vcpu_load(vcpu);
-
         regs->pc = kvmppc_get_pc(vcpu);
         regs->cr = kvmppc_get_cr(vcpu);
         regs->ctr = kvmppc_get_ctr(vcpu);
@@ -1069,8 +1067,6 @@ int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
         for (i = 0; i < ARRAY_SIZE(regs->gpr); i++)
                 regs->gpr[i] = kvmppc_get_gpr(vcpu, i);
 
-        vcpu_put(vcpu);
-
         return 0;
 }
 
@@ -1078,8 +1074,6 @@ int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 {
         int i;
 
-        vcpu_load(vcpu);
-
         kvmppc_set_pc(vcpu, regs->pc);
         kvmppc_set_cr(vcpu, regs->cr);
         kvmppc_set_ctr(vcpu, regs->ctr);
@@ -1099,8 +1093,6 @@ int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
         for (i = 0; i < ARRAY_SIZE(regs->gpr); i++)
                 kvmppc_set_gpr(vcpu, i, regs->gpr[i]);
 
-        vcpu_put(vcpu);
-
         return 0;
 }
 
@@ -1110,8 +1102,6 @@ int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
         struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
         int i;
 
-        vcpu_load(vcpu);
-
         sregs->pvr = vcpu->arch.pvr;
 
         sregs->u.s.sdr1 = to_book3s(vcpu)->sdr1;
@@ -1131,8 +1121,6 @@ int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
                 }
         }
 
-        vcpu_put(vcpu);
-
         return 0;
 }
 
@@ -1142,8 +1130,6 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
         struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
         int i;
 
-        vcpu_load(vcpu);
-
         kvmppc_set_pvr(vcpu, sregs->pvr);
 
         vcpu3s->sdr1 = sregs->u.s.sdr1;
@@ -1171,8 +1157,6 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
         /* Flush the MMU after messing with the segments */
         kvmppc_mmu_pte_flush(vcpu, 0, 0);
 
-        vcpu_put(vcpu);
-
         return 0;
 }
 
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index a33ab8cc2cc..b687f430f8c 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -485,8 +485,6 @@ int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 {
         int i;
 
-        vcpu_load(vcpu);
-
         regs->pc = vcpu->arch.pc;
         regs->cr = kvmppc_get_cr(vcpu);
         regs->ctr = vcpu->arch.ctr;
@@ -507,8 +505,6 @@ int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
         for (i = 0; i < ARRAY_SIZE(regs->gpr); i++)
                 regs->gpr[i] = kvmppc_get_gpr(vcpu, i);
 
-        vcpu_put(vcpu);
-
         return 0;
 }
 
@@ -516,8 +512,6 @@ int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 {
         int i;
 
-        vcpu_load(vcpu);
-
         vcpu->arch.pc = regs->pc;
         kvmppc_set_cr(vcpu, regs->cr);
         vcpu->arch.ctr = regs->ctr;
@@ -537,8 +531,6 @@ int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
         for (i = 0; i < ARRAY_SIZE(regs->gpr); i++)
                 kvmppc_set_gpr(vcpu, i, regs->gpr[i]);
 
-        vcpu_put(vcpu);
-
         return 0;
 }
 
@@ -569,9 +561,7 @@ int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
 {
         int r;
 
-        vcpu_load(vcpu);
         r = kvmppc_core_vcpu_translate(vcpu, tr);
-        vcpu_put(vcpu);
         return r;
 }
 
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 9b8683f39e0..e0fae7a618c 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -423,8 +423,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
         int r;
         sigset_t sigsaved;
 
-        vcpu_load(vcpu);
-
         if (vcpu->sigset_active)
                 sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);
 
@@ -456,8 +454,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
         if (vcpu->sigset_active)
                 sigprocmask(SIG_SETMASK, &sigsaved, NULL);
 
-        vcpu_put(vcpu);
-
         return r;
 }
 
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index ae370581687..0d0e0add020 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -371,55 +371,43 @@ static int kvm_arch_vcpu_ioctl_initial_reset(struct kvm_vcpu *vcpu)
 
 int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 {
-        vcpu_load(vcpu);
         memcpy(&vcpu->arch.guest_gprs, &regs->gprs, sizeof(regs->gprs));
-        vcpu_put(vcpu);
         return 0;
 }
 
 int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 {
-        vcpu_load(vcpu);
         memcpy(&regs->gprs, &vcpu->arch.guest_gprs, sizeof(regs->gprs));
-        vcpu_put(vcpu);
         return 0;
 }
 
 int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
                                   struct kvm_sregs *sregs)
 {
-        vcpu_load(vcpu);
         memcpy(&vcpu->arch.guest_acrs, &sregs->acrs, sizeof(sregs->acrs));
         memcpy(&vcpu->arch.sie_block->gcr, &sregs->crs, sizeof(sregs->crs));
-        vcpu_put(vcpu);
         return 0;
 }
 
 int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
                                   struct kvm_sregs *sregs)
 {
-        vcpu_load(vcpu);
         memcpy(&sregs->acrs, &vcpu->arch.guest_acrs, sizeof(sregs->acrs));
         memcpy(&sregs->crs, &vcpu->arch.sie_block->gcr, sizeof(sregs->crs));
-        vcpu_put(vcpu);
         return 0;
 }
 
 int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 {
-        vcpu_load(vcpu);
         memcpy(&vcpu->arch.guest_fpregs.fprs, &fpu->fprs, sizeof(fpu->fprs));
         vcpu->arch.guest_fpregs.fpc = fpu->fpc;
-        vcpu_put(vcpu);
         return 0;
 }
 
 int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 {
-        vcpu_load(vcpu);
         memcpy(&fpu->fprs, &vcpu->arch.guest_fpregs.fprs, sizeof(fpu->fprs));
         fpu->fpc = vcpu->arch.guest_fpregs.fpc;
-        vcpu_put(vcpu);
         return 0;
 }
 
@@ -498,8 +486,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
         int rc;
         sigset_t sigsaved;
 
-        vcpu_load(vcpu);
-
 rerun_vcpu:
         if (vcpu->requests)
                 if (test_and_clear_bit(KVM_REQ_MMU_RELOAD, &vcpu->requests))
@@ -568,8 +554,6 @@ rerun_vcpu:
         if (vcpu->sigset_active)
                 sigprocmask(SIG_SETMASK, &sigsaved, NULL);
 
-        vcpu_put(vcpu);
-
         vcpu->stat.exit_userspace++;
         return rc;
 }
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b05321adfd2..5acd21245fc 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4773,8 +4773,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
         int r;
         sigset_t sigsaved;
 
-        vcpu_load(vcpu);
-
         if (vcpu->sigset_active)
                 sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);
 
@@ -4815,14 +4813,11 @@ out:
         if (vcpu->sigset_active)
                 sigprocmask(SIG_SETMASK, &sigsaved, NULL);
 
-        vcpu_put(vcpu);
         return r;
 }
 
 int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 {
-        vcpu_load(vcpu);
-
         regs->rax = kvm_register_read(vcpu, VCPU_REGS_RAX);
         regs->rbx = kvm_register_read(vcpu, VCPU_REGS_RBX);
         regs->rcx = kvm_register_read(vcpu, VCPU_REGS_RCX);
@@ -4845,15 +4840,11 @@ int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
         regs->rip = kvm_rip_read(vcpu);
         regs->rflags = kvm_get_rflags(vcpu);
 
-        vcpu_put(vcpu);
-
         return 0;
 }
 
 int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 {
-        vcpu_load(vcpu);
-
         kvm_register_write(vcpu, VCPU_REGS_RAX, regs->rax);
         kvm_register_write(vcpu, VCPU_REGS_RBX, regs->rbx);
         kvm_register_write(vcpu, VCPU_REGS_RCX, regs->rcx);
@@ -4878,8 +4869,6 @@ int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 
         vcpu->arch.exception.pending = false;
 
-        vcpu_put(vcpu);
-
         return 0;
 }
 
@@ -4898,8 +4887,6 @@ int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
 {
         struct desc_ptr dt;
 
-        vcpu_load(vcpu);
-
         kvm_get_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
         kvm_get_segment(vcpu, &sregs->ds, VCPU_SREG_DS);
         kvm_get_segment(vcpu, &sregs->es, VCPU_SREG_ES);
@@ -4931,26 +4918,20 @@ int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
                 set_bit(vcpu->arch.interrupt.nr,
                         (unsigned long *)sregs->interrupt_bitmap);
 
-        vcpu_put(vcpu);
-
         return 0;
 }
 
 int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
                                     struct kvm_mp_state *mp_state)
 {
-        vcpu_load(vcpu);
         mp_state->mp_state = vcpu->arch.mp_state;
-        vcpu_put(vcpu);
         return 0;
 }
 
 int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
                                     struct kvm_mp_state *mp_state)
 {
-        vcpu_load(vcpu);
         vcpu->arch.mp_state = mp_state->mp_state;
-        vcpu_put(vcpu);
         return 0;
 }
 
@@ -4996,8 +4977,6 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
         int pending_vec, max_bits;
         struct desc_ptr dt;
 
-        vcpu_load(vcpu);
-
         dt.size = sregs->idt.limit;
         dt.address = sregs->idt.base;
         kvm_x86_ops->set_idt(vcpu, &dt);
@@ -5057,8 +5036,6 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
             !is_protmode(vcpu))
                 vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
 
-        vcpu_put(vcpu);
-
         return 0;
 }
 
@@ -5068,12 +5045,10 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
         unsigned long rflags;
         int i, r;
 
-        vcpu_load(vcpu);
-
         if (dbg->control & (KVM_GUESTDBG_INJECT_DB | KVM_GUESTDBG_INJECT_BP)) {
                 r = -EBUSY;
                 if (vcpu->arch.exception.pending)
-                        goto unlock_out;
+                        goto out;
                 if (dbg->control & KVM_GUESTDBG_INJECT_DB)
                         kvm_queue_exception(vcpu, DB_VECTOR);
                 else
@@ -5115,8 +5090,7 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
 
         r = 0;
 
-unlock_out:
-        vcpu_put(vcpu);
+out:
 
         return r;
 }
@@ -5152,7 +5126,6 @@ int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
         gpa_t gpa;
         int idx;
 
-        vcpu_load(vcpu);
         idx = srcu_read_lock(&vcpu->kvm->srcu);
         gpa = kvm_mmu_gva_to_gpa_system(vcpu, vaddr, NULL);
         srcu_read_unlock(&vcpu->kvm->srcu, idx);
@@ -5160,7 +5133,6 @@ int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
         tr->valid = gpa != UNMAPPED_GVA;
         tr->writeable = 1;
         tr->usermode = 0;
-        vcpu_put(vcpu);
 
         return 0;
 }
@@ -5169,8 +5141,6 @@ int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 {
         struct fxsave *fxsave = (struct fxsave *)&vcpu->arch.guest_fx_image;
 
-        vcpu_load(vcpu);
-
         memcpy(fpu->fpr, fxsave->st_space, 128);
         fpu->fcw = fxsave->cwd;
         fpu->fsw = fxsave->swd;
@@ -5180,8 +5150,6 @@ int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
         fpu->last_dp = fxsave->rdp;
         memcpy(fpu->xmm, fxsave->xmm_space, sizeof fxsave->xmm_space);
 
-        vcpu_put(vcpu);
-
         return 0;
 }
 
@@ -5189,8 +5157,6 @@ int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 {
         struct fxsave *fxsave = (struct fxsave *)&vcpu->arch.guest_fx_image;
 
-        vcpu_load(vcpu);
-
         memcpy(fxsave->st_space, fpu->fpr, 128);
         fxsave->cwd = fpu->fcw;
         fxsave->swd = fpu->fsw;
@@ -5200,8 +5166,6 @@ int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
         fxsave->rdp = fpu->last_dp;
         memcpy(fxsave->xmm_space, fpu->xmm, sizeof fxsave->xmm_space);
 
-        vcpu_put(vcpu);
-
         return 0;
 }
 
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 187aa8d984a..e0fb0988a3f 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1392,6 +1392,18 @@ static long kvm_vcpu_ioctl(struct file *filp,
 
         if (vcpu->kvm->mm != current->mm)
                 return -EIO;
+
+#if defined(CONFIG_S390) || defined(CONFIG_PPC)
+        /*
+         * Special cases: vcpu ioctls that are asynchronous to vcpu execution,
+         * so vcpu_load() would break it.
+         */
+        if (ioctl == KVM_S390_INTERRUPT || ioctl == KVM_INTERRUPT)
+                return kvm_arch_vcpu_ioctl(filp, ioctl, arg);
+#endif
+
+
+        vcpu_load(vcpu);
         switch (ioctl) {
         case KVM_RUN:
                 r = -EINVAL;
@@ -1566,9 +1578,12 @@ out_free2:
                 break;
         }
         default:
+                vcpu_put(vcpu);
                 r = kvm_arch_vcpu_ioctl(filp, ioctl, arg);
+                vcpu_load(vcpu);
         }
 out:
+        vcpu_put(vcpu);
         kfree(fpu);
         kfree(kvm_sregs);
         return r;