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From: Marc Zyngier <maz@kernel.org>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, kernel-team@android.com,
	Steven Price <steven.price@arm.com>,
	linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu
Subject: [PATCH 3/4] KVM: arm64: pvtime: Ensure task delay accounting is enabled
Date: Mon, 29 Jun 2020 17:25:18 +0100
Message-ID: <20200629162519.825200-4-maz@kernel.org> (raw)
In-Reply-To: <20200629162519.825200-1-maz@kernel.org>

From: Andrew Jones <drjones@redhat.com>

Ensure we're actually accounting run_delay before we claim that we'll
expose it to the guest. If we're not, then we just pretend like steal
time isn't supported in order to avoid any confusion.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200622142710.18677-1-drjones@redhat.com
---
 arch/arm64/kvm/pvtime.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kvm/pvtime.c b/arch/arm64/kvm/pvtime.c
index 1e0f4c284888..f7b52ce1557e 100644
--- a/arch/arm64/kvm/pvtime.c
+++ b/arch/arm64/kvm/pvtime.c
@@ -3,6 +3,7 @@
 
 #include <linux/arm-smccc.h>
 #include <linux/kvm_host.h>
+#include <linux/sched/stat.h>
 
 #include <asm/kvm_mmu.h>
 #include <asm/pvclock-abi.h>
@@ -73,6 +74,11 @@ gpa_t kvm_init_stolen_time(struct kvm_vcpu *vcpu)
 	return base;
 }
 
+static bool kvm_arm_pvtime_supported(void)
+{
+	return !!sched_info_on();
+}
+
 int kvm_arm_pvtime_set_attr(struct kvm_vcpu *vcpu,
 			    struct kvm_device_attr *attr)
 {
@@ -82,7 +88,8 @@ int kvm_arm_pvtime_set_attr(struct kvm_vcpu *vcpu,
 	int ret = 0;
 	int idx;
 
-	if (attr->attr != KVM_ARM_VCPU_PVTIME_IPA)
+	if (!kvm_arm_pvtime_supported() ||
+	    attr->attr != KVM_ARM_VCPU_PVTIME_IPA)
 		return -ENXIO;
 
 	if (get_user(ipa, user))
@@ -110,7 +117,8 @@ int kvm_arm_pvtime_get_attr(struct kvm_vcpu *vcpu,
 	u64 __user *user = (u64 __user *)attr->addr;
 	u64 ipa;
 
-	if (attr->attr != KVM_ARM_VCPU_PVTIME_IPA)
+	if (!kvm_arm_pvtime_supported() ||
+	    attr->attr != KVM_ARM_VCPU_PVTIME_IPA)
 		return -ENXIO;
 
 	ipa = vcpu->arch.steal.base;
@@ -125,7 +133,8 @@ int kvm_arm_pvtime_has_attr(struct kvm_vcpu *vcpu,
 {
 	switch (attr->attr) {
 	case KVM_ARM_VCPU_PVTIME_IPA:
-		return 0;
+		if (kvm_arm_pvtime_supported())
+			return 0;
 	}
 	return -ENXIO;
 }
-- 
2.27.0

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  parent reply index

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-29 16:25 [GIT PULL] KVM/arm64 fixes for 5.8, take #2 Marc Zyngier
2020-06-29 16:25 ` [PATCH 1/4] KVM: arm64: Annotate hyp NMI-related functions as __always_inline Marc Zyngier
2020-06-29 16:25 ` [PATCH 2/4] KVM: arm64: Fix kvm_reset_vcpu() return code being incorrect with SVE Marc Zyngier
2020-06-29 16:25 ` Marc Zyngier [this message]
2020-06-29 16:25 ` [PATCH 4/4] KVM: arm64: vgic-v4: Plug race between non-residency and v4.1 doorbell Marc Zyngier
2020-07-01 14:24 ` [GIT PULL] KVM/arm64 fixes for 5.8, take #2 Paolo Bonzini

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