[PATCH 3/7] KVM: move vcpu locking to dispatcher for generic vcpu ioctls

[Avi Kivity <avi@redhat.com>]

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>
---
 arch/ia64/kvm/kvm-ia64.c   |   11 -----------
 arch/powerpc/kvm/book3s.c  |   16 ----------------
 arch/powerpc/kvm/booke.c   |   10 ----------
 arch/powerpc/kvm/powerpc.c |    4 ----
 arch/s390/kvm/kvm-s390.c   |   16 ----------------
 arch/x86/kvm/x86.c         |   36 ++----------------------------------
 virt/kvm/kvm_main.c        |   15 +++++++++++++++
 7 files changed, 17 insertions(+), 91 deletions(-)

diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index d5f4e91..29f6075 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -724,8 +724,6 @@ 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);
 
@@ -747,7 +745,6 @@ out:
 	if (vcpu->sigset_active)
 		sigprocmask(SIG_SETMASK, &sigsaved, NULL);
 
-	vcpu_put(vcpu);
 	return r;
 }
 
@@ -882,8 +879,6 @@ 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];
@@ -930,8 +925,6 @@ 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;
 }
 
@@ -1966,9 +1959,7 @@ 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;
 }
 
@@ -1999,10 +1990,8 @@ 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 b998abf..f6eac2f 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 a33ab8c..b687f43 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 9b8683f..e0fae7a 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 8093e6f..e80f55e 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 f54ec24..eedb23b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4765,8 +4765,6 @@ 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);
 
@@ -4807,14 +4805,11 @@ 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);
@@ -4837,15 +4832,11 @@ 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);
@@ -4870,8 +4861,6 @@ 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;
 }
 
@@ -4890,8 +4879,6 @@ 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);
@@ -4923,8 +4910,6 @@ 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;
 }
 
@@ -4988,8 +4973,6 @@ 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);
@@ -5049,8 +5032,6 @@ 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;
 }
 
@@ -5060,12 +5041,10 @@ 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
@@ -5107,8 +5086,7 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
 
 	r = 0;
 
-unlock_out:
-	vcpu_put(vcpu);
+out:
 
 	return r;
 }
@@ -5144,7 +5122,6 @@ 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);
@@ -5152,7 +5129,6 @@ 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;
 }
@@ -5161,8 +5137,6 @@ 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;
@@ -5172,8 +5146,6 @@ 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;
 }
 
@@ -5181,8 +5153,6 @@ 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;
@@ -5192,8 +5162,6 @@ 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 f032806..08b2ccd 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1378,6 +1378,18 @@ 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;
@@ -1552,9 +1564,12 @@ 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;
-- 
1.7.0.4