From: christoffer.dall@linaro.org (Christoffer Dall)
To: linux-arm-kernel@lists.infradead.org
Subject: [GIT PULL 04/12] arm/arm64: KVM: Clarify KVM_ARM_VCPU_INIT ABI
Date: Mon, 15 Dec 2014 12:41:51 +0100 [thread overview]
Message-ID: <1418643719-25966-5-git-send-email-christoffer.dall@linaro.org> (raw)
In-Reply-To: <1418643719-25966-1-git-send-email-christoffer.dall@linaro.org>
It is not clear that this ioctl can be called multiple times for a given
vcpu. Userspace already does this, so clarify the ABI.
Also specify that userspace is expected to always make secondary and
subsequent calls to the ioctl with the same parameters for the VCPU as
the initial call (which userspace also already does).
Add code to check that userspace doesn't violate that ABI in the future,
and move the kvm_vcpu_set_target() function which is currently
duplicated between the 32-bit and 64-bit versions in guest.c to a common
static function in arm.c, shared between both architectures.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
---
Documentation/virtual/kvm/api.txt | 5 +++++
arch/arm/include/asm/kvm_host.h | 2 --
arch/arm/kvm/arm.c | 43 +++++++++++++++++++++++++++++++++++++++
arch/arm/kvm/guest.c | 25 -----------------------
arch/arm64/include/asm/kvm_host.h | 2 --
arch/arm64/kvm/guest.c | 25 -----------------------
6 files changed, 48 insertions(+), 54 deletions(-)
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index bb82a90..81f1b97 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2453,6 +2453,11 @@ return ENOEXEC for that vcpu.
Note that because some registers reflect machine topology, all vcpus
should be created before this ioctl is invoked.
+Userspace can call this function multiple times for a given vcpu, including
+after the vcpu has been run. This will reset the vcpu to its initial
+state. All calls to this function after the initial call must use the same
+target and same set of feature flags, otherwise EINVAL will be returned.
+
Possible features:
- KVM_ARM_VCPU_POWER_OFF: Starts the CPU in a power-off state.
Depends on KVM_CAP_ARM_PSCI. If not set, the CPU will be powered on
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 53036e2..254e065 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -150,8 +150,6 @@ struct kvm_vcpu_stat {
u32 halt_wakeup;
};
-int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
- const struct kvm_vcpu_init *init);
int kvm_vcpu_preferred_target(struct kvm_vcpu_init *init);
unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu);
int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *indices);
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 24c9ca4..4043769 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -263,6 +263,7 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
{
/* Force users to call KVM_ARM_VCPU_INIT */
vcpu->arch.target = -1;
+ bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);
/* Set up the timer */
kvm_timer_vcpu_init(vcpu);
@@ -649,6 +650,48 @@ int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level,
return -EINVAL;
}
+static int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
+ const struct kvm_vcpu_init *init)
+{
+ unsigned int i;
+ int phys_target = kvm_target_cpu();
+
+ if (init->target != phys_target)
+ return -EINVAL;
+
+ /*
+ * Secondary and subsequent calls to KVM_ARM_VCPU_INIT must
+ * use the same target.
+ */
+ if (vcpu->arch.target != -1 && vcpu->arch.target != init->target)
+ return -EINVAL;
+
+ /* -ENOENT for unknown features, -EINVAL for invalid combinations. */
+ for (i = 0; i < sizeof(init->features) * 8; i++) {
+ bool set = (init->features[i / 32] & (1 << (i % 32)));
+
+ if (set && i >= KVM_VCPU_MAX_FEATURES)
+ return -ENOENT;
+
+ /*
+ * Secondary and subsequent calls to KVM_ARM_VCPU_INIT must
+ * use the same feature set.
+ */
+ if (vcpu->arch.target != -1 && i < KVM_VCPU_MAX_FEATURES &&
+ test_bit(i, vcpu->arch.features) != set)
+ return -EINVAL;
+
+ if (set)
+ set_bit(i, vcpu->arch.features);
+ }
+
+ vcpu->arch.target = phys_target;
+
+ /* Now we know what it is, we can reset it. */
+ return kvm_reset_vcpu(vcpu);
+}
+
+
static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu,
struct kvm_vcpu_init *init)
{
diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c
index 8c97208..384bab6 100644
--- a/arch/arm/kvm/guest.c
+++ b/arch/arm/kvm/guest.c
@@ -273,31 +273,6 @@ int __attribute_const__ kvm_target_cpu(void)
}
}
-int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
- const struct kvm_vcpu_init *init)
-{
- unsigned int i;
-
- /* We can only cope with guest==host and only on A15/A7 (for now). */
- if (init->target != kvm_target_cpu())
- return -EINVAL;
-
- vcpu->arch.target = init->target;
- bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);
-
- /* -ENOENT for unknown features, -EINVAL for invalid combinations. */
- for (i = 0; i < sizeof(init->features) * 8; i++) {
- if (test_bit(i, (void *)init->features)) {
- if (i >= KVM_VCPU_MAX_FEATURES)
- return -ENOENT;
- set_bit(i, vcpu->arch.features);
- }
- }
-
- /* Now we know what it is, we can reset it. */
- return kvm_reset_vcpu(vcpu);
-}
-
int kvm_vcpu_preferred_target(struct kvm_vcpu_init *init)
{
int target = kvm_target_cpu();
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 2012c4b..65c6152 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -165,8 +165,6 @@ struct kvm_vcpu_stat {
u32 halt_wakeup;
};
-int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
- const struct kvm_vcpu_init *init);
int kvm_vcpu_preferred_target(struct kvm_vcpu_init *init);
unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu);
int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *indices);
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 84d5959..9535bd5 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -296,31 +296,6 @@ int __attribute_const__ kvm_target_cpu(void)
return -EINVAL;
}
-int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
- const struct kvm_vcpu_init *init)
-{
- unsigned int i;
- int phys_target = kvm_target_cpu();
-
- if (init->target != phys_target)
- return -EINVAL;
-
- vcpu->arch.target = phys_target;
- bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);
-
- /* -ENOENT for unknown features, -EINVAL for invalid combinations. */
- for (i = 0; i < sizeof(init->features) * 8; i++) {
- if (init->features[i / 32] & (1 << (i % 32))) {
- if (i >= KVM_VCPU_MAX_FEATURES)
- return -ENOENT;
- set_bit(i, vcpu->arch.features);
- }
- }
-
- /* Now we know what it is, we can reset it. */
- return kvm_reset_vcpu(vcpu);
-}
-
int kvm_vcpu_preferred_target(struct kvm_vcpu_init *init)
{
int target = kvm_target_cpu();
--
2.1.2.330.g565301e.dirty
next prev parent reply other threads:[~2014-12-15 11:41 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-15 11:41 [GIT PULL 00/12] KVM/ARM Changes for v3.19 - Take 2 Christoffer Dall
2014-12-15 11:41 ` [GIT PULL 01/12] arm/arm64: KVM: Don't clear the VCPU_POWER_OFF flag Christoffer Dall
2014-12-15 11:41 ` [GIT PULL 02/12] arm/arm64: KVM: Correct KVM_ARM_VCPU_INIT power off option Christoffer Dall
2014-12-15 11:41 ` [GIT PULL 03/12] arm/arm64: KVM: Reset the HCR on each vcpu when resetting the vcpu Christoffer Dall
2014-12-15 11:41 ` Christoffer Dall [this message]
2014-12-15 11:41 ` [GIT PULL 05/12] arm/arm64: KVM: Turn off vcpus on PSCI shutdown/reboot Christoffer Dall
2014-12-15 11:41 ` [GIT PULL 06/12] arm/arm64: KVM: Introduce stage2_unmap_vm Christoffer Dall
2014-12-15 11:41 ` [GIT PULL 07/12] arm/arm64: KVM: vgic: move reset initialization into vgic_init_maps() Christoffer Dall
2014-12-15 11:41 ` [GIT PULL 08/12] arm/arm64: KVM: Rename vgic_initialized to vgic_ready Christoffer Dall
2014-12-15 11:41 ` [GIT PULL 09/12] arm/arm64: KVM: Add (new) vgic_initialized macro Christoffer Dall
2014-12-15 11:41 ` [GIT PULL 10/12] arm/arm64: KVM: Don't allow creating VCPUs after vgic_initialized Christoffer Dall
2014-12-15 11:41 ` [GIT PULL 11/12] arm/arm64: KVM: Initialize the vgic on-demand when injecting IRQs Christoffer Dall
2014-12-15 11:41 ` [GIT PULL 12/12] arm/arm64: KVM: Require in-kernel vgic for the arch timers Christoffer Dall
2014-12-15 12:08 ` [GIT PULL 00/12] KVM/ARM Changes for v3.19 - Take 2 Paolo Bonzini
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