[PATCH MANUALSEL 5.10 1/5] KVM: selftests: Fix kvm_vm_free() in cr4_cpuid_sync and vmx_tsc_adjust tests

[PATCH MANUALSEL 5.10 1/5] KVM: selftests: Fix kvm_vm_free() in cr4_cpuid_sync and vmx_tsc_adjust tests

[Sasha Levin]

From: Thomas Huth <thuth@redhat.com>

[ Upstream commit 22d7108ce47290d47e1ea83a28fbfc85e0ecf97e ]

The kvm_vm_free() statement here is currently dead code, since the loop
in front of it can only be left with the "goto done" that jumps right
after the kvm_vm_free(). Fix it by swapping the locations of the "done"
label and the kvm_vm_free().

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210826074928.240942-1-thuth@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/kvm/x86_64/cr4_cpuid_sync_test.c | 3 +--
 tools/testing/selftests/kvm/x86_64/vmx_tsc_adjust_test.c | 2 +-
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/kvm/x86_64/cr4_cpuid_sync_test.c b/tools/testing/selftests/kvm/x86_64/cr4_cpuid_sync_test.c
index 140e91901582b..4d259294804fc 100644
--- a/tools/testing/selftests/kvm/x86_64/cr4_cpuid_sync_test.c
+++ b/tools/testing/selftests/kvm/x86_64/cr4_cpuid_sync_test.c
@@ -110,8 +110,7 @@ int main(int argc, char *argv[])
 		}
 	}
 
-	kvm_vm_free(vm);
-
 done:
+	kvm_vm_free(vm);
 	return 0;
 }
diff --git a/tools/testing/selftests/kvm/x86_64/vmx_tsc_adjust_test.c b/tools/testing/selftests/kvm/x86_64/vmx_tsc_adjust_test.c
index fbe8417cbc2c3..8b9fa313adf21 100644
--- a/tools/testing/selftests/kvm/x86_64/vmx_tsc_adjust_test.c
+++ b/tools/testing/selftests/kvm/x86_64/vmx_tsc_adjust_test.c
@@ -162,7 +162,7 @@ int main(int argc, char *argv[])
 		}
 	}
 
-	kvm_vm_free(vm);
 done:
+	kvm_vm_free(vm);
 	return 0;
 }
-- 
2.33.0

[PATCH MANUALSEL 5.10 2/5] KVM: s390: Cap KVM_CAP_NR_VCPUS by num_online_cpus()

[Sasha Levin]

From: Vitaly Kuznetsov <vkuznets@redhat.com>

[ Upstream commit 82cc27eff4486f8e79ef8faac1af1f5573039aa4 ]

KVM_CAP_NR_VCPUS is a legacy advisory value which on other architectures
return num_online_cpus() caped by KVM_CAP_NR_VCPUS or something else
(ppc and arm64 are special cases). On s390, KVM_CAP_NR_VCPUS returns
the same as KVM_CAP_MAX_VCPUS and this may turn out to be a bad
'advice'. Switch s390 to returning caped num_online_cpus() too.

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Message-Id: <20211116163443.88707-6-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/s390/kvm/kvm-s390.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 00f03f363c9b0..25ca18ed07bdc 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -564,6 +564,8 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 			r = KVM_MAX_VCPUS;
 		else if (sclp.has_esca && sclp.has_64bscao)
 			r = KVM_S390_ESCA_CPU_SLOTS;
+		if (ext == KVM_CAP_NR_VCPUS)
+			r = min_t(unsigned int, num_online_cpus(), r);
 		break;
 	case KVM_CAP_S390_COW:
 		r = MACHINE_HAS_ESOP;
-- 
2.33.0

[PATCH MANUALSEL 5.10 3/5] KVM: PPC: Cap KVM_CAP_NR_VCPUS by KVM_CAP_MAX_VCPUS

[Sasha Levin]

From: Vitaly Kuznetsov <vkuznets@redhat.com>

[ Upstream commit b7915d55b1ac0e68a7586697fa2d06c018135c49 ]

It doesn't make sense to return the recommended maximum number of
vCPUs which exceeds the maximum possible number of vCPUs.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211116163443.88707-4-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/kvm/powerpc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 543db9157f3b1..e0e8ec387970d 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -641,9 +641,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 		 * implementations just count online CPUs.
 		 */
 		if (hv_enabled)
-			r = num_present_cpus();
+			r = min_t(unsigned int, num_present_cpus(), KVM_MAX_VCPUS);
 		else
-			r = num_online_cpus();
+			r = min_t(unsigned int, num_online_cpus(), KVM_MAX_VCPUS);
 		break;
 	case KVM_CAP_MAX_VCPUS:
 		r = KVM_MAX_VCPUS;
-- 
2.33.0

[PATCH MANUALSEL 5.10 4/5] KVM: MIPS: Cap KVM_CAP_NR_VCPUS by KVM_CAP_MAX_VCPUS

[Sasha Levin]

From: Vitaly Kuznetsov <vkuznets@redhat.com>

[ Upstream commit 57a2e13ebdda8b65602b44ec8b80e385603eb84c ]

It doesn't make sense to return the recommended maximum number of
vCPUs which exceeds the maximum possible number of vCPUs.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211116163443.88707-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/mips/kvm/mips.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index 3d6a7f5827b17..a9f1f37009850 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -1074,7 +1074,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 		r = 1;
 		break;
 	case KVM_CAP_NR_VCPUS:
-		r = num_online_cpus();
+		r = min_t(unsigned int, num_online_cpus(), KVM_MAX_VCPUS);
 		break;
 	case KVM_CAP_MAX_VCPUS:
 		r = KVM_MAX_VCPUS;
-- 
2.33.0

[PATCH MANUALSEL 5.10 5/5] KVM: arm64: Cap KVM_CAP_NR_VCPUS by kvm_arm_default_max_vcpus()

[Sasha Levin]

From: Vitaly Kuznetsov <vkuznets@redhat.com>

[ Upstream commit f60a00d7295057cb4baea5a321501efc72794453 ]

Generally, it doesn't make sense to return the recommended maximum number
of vCPUs which exceeds the maximum possible number of vCPUs.

Note: ARM64 is special as the value returned by KVM_CAP_MAX_VCPUS differs
depending on whether it is a system-wide ioctl or a per-VM one. Previously,
KVM_CAP_NR_VCPUS didn't have this difference and it seems preferable to
keep the status quo. Cap KVM_CAP_NR_VCPUS by kvm_arm_default_max_vcpus()
which is what gets returned by system-wide KVM_CAP_MAX_VCPUS.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211116163443.88707-2-vkuznets@redhat.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/arm64/kvm/arm.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 5bc978be80434..7737a10ba735f 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -204,7 +204,14 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 		r = 1;
 		break;
 	case KVM_CAP_NR_VCPUS:
-		r = num_online_cpus();
+		/*
+		 * ARM64 treats KVM_CAP_NR_CPUS differently from all other
+		 * architectures, as it does not always bound it to
+		 * KVM_CAP_MAX_VCPUS. It should not matter much because
+		 * this is just an advisory value.
+		 */
+		r = min_t(unsigned int, num_online_cpus(),
+			  kvm_arm_default_max_vcpus());
 		break;
 	case KVM_CAP_MAX_VCPUS:
 	case KVM_CAP_MAX_VCPU_ID:
-- 
2.33.0