LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Thomas Huth <thuth@redhat.com>
To: Christian Borntraeger <borntraeger@de.ibm.com>,
	Janosch Frank <frankja@linux.ibm.com>,
	kvm@vger.kernel.org
Cc: "Paolo Bonzini" <pbonzini@redhat.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>,
	"Shuah Khan" <shuah@kernel.org>,
	"David Hildenbrand" <david@redhat.com>,
	"Cornelia Huck" <cohuck@redhat.com>,
	"Andrew Jones" <drjones@redhat.com>,
	linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
	linux-s390@vger.kernel.org
Subject: [PATCH 8/9] KVM: s390: Do not report unusabled IDs via KVM_CAP_MAX_VCPU_ID
Date: Thu, 23 May 2019 18:43:08 +0200	[thread overview]
Message-ID: <20190523164309.13345-9-thuth@redhat.com> (raw)
In-Reply-To: <20190523164309.13345-1-thuth@redhat.com>

KVM_CAP_MAX_VCPU_ID is currently always reporting KVM_MAX_VCPU_ID on all
architectures. However, on s390x, the amount of usable CPUs is determined
during runtime - it is depending on the features of the machine the code
is running on. Since we are using the vcpu_id as an index into the SCA
structures that are defined by the hardware (see e.g. the sca_add_vcpu()
function), it is not only the amount of CPUs that is limited by the hard-
ware, but also the range of IDs that we can use.
Thus KVM_CAP_MAX_VCPU_ID must be determined during runtime on s390x, too.
So the handling of KVM_CAP_MAX_VCPU_ID has to be moved from the common
code into the architecture specific code, and on s390x we have to return
the same value here as for KVM_CAP_MAX_VCPUS.
This problem has been discovered with the kvm_create_max_vcpus selftest.
With this change applied, the selftest now passes on s390x, too.

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 arch/mips/kvm/mips.c       | 3 +++
 arch/powerpc/kvm/powerpc.c | 3 +++
 arch/s390/kvm/kvm-s390.c   | 1 +
 arch/x86/kvm/x86.c         | 3 +++
 virt/kvm/arm/arm.c         | 3 +++
 virt/kvm/kvm_main.c        | 2 --
 6 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index 6d0517ac18e5..0369f26ab96d 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -1122,6 +1122,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_MAX_VCPUS:
 		r = KVM_MAX_VCPUS;
 		break;
+	case KVM_CAP_MAX_VCPU_ID:
+		r = KVM_MAX_VCPU_ID;
+		break;
 	case KVM_CAP_MIPS_FPU:
 		/* We don't handle systems with inconsistent cpu_has_fpu */
 		r = !!raw_cpu_has_fpu;
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 3393b166817a..aa3a678711be 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -657,6 +657,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_MAX_VCPUS:
 		r = KVM_MAX_VCPUS;
 		break;
+	case KVM_CAP_MAX_VCPU_ID:
+		r = KVM_MAX_VCPU_ID;
+		break;
 #ifdef CONFIG_PPC_BOOK3S_64
 	case KVM_CAP_PPC_GET_SMMU_INFO:
 		r = 1;
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 8d6d75db8de6..871d2e99b156 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -539,6 +539,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 		break;
 	case KVM_CAP_NR_VCPUS:
 	case KVM_CAP_MAX_VCPUS:
+	case KVM_CAP_MAX_VCPU_ID:
 		r = KVM_S390_BSCA_CPU_SLOTS;
 		if (!kvm_s390_use_sca_entries())
 			r = KVM_MAX_VCPUS;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 536b78c4af6e..09a07d6a154e 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3122,6 +3122,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_MAX_VCPUS:
 		r = KVM_MAX_VCPUS;
 		break;
+	case KVM_CAP_MAX_VCPU_ID:
+		r = KVM_MAX_VCPU_ID;
+		break;
 	case KVM_CAP_PV_MMU:	/* obsolete */
 		r = 0;
 		break;
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index 90cedebaeb94..7eeebe5e9da2 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -224,6 +224,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_MAX_VCPUS:
 		r = KVM_MAX_VCPUS;
 		break;
+	case KVM_CAP_MAX_VCPU_ID:
+		r = KVM_MAX_VCPU_ID;
+		break;
 	case KVM_CAP_MSI_DEVID:
 		if (!kvm)
 			r = -EINVAL;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index f0d13d9d125d..c09259dd6286 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -3146,8 +3146,6 @@ static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)
 	case KVM_CAP_MULTI_ADDRESS_SPACE:
 		return KVM_ADDRESS_SPACE_NUM;
 #endif
-	case KVM_CAP_MAX_VCPU_ID:
-		return KVM_MAX_VCPU_ID;
 	case KVM_CAP_NR_MEMSLOTS:
 		return KVM_USER_MEM_SLOTS;
 	default:
-- 
2.21.0


  parent reply	other threads:[~2019-05-23 16:43 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-23 16:43 [PATCH v1 0/9] KVM selftests for s390x Thomas Huth
2019-05-23 16:43 ` [PATCH 1/9] KVM: selftests: Wrap vcpu_nested_state_get/set functions with x86 guard Thomas Huth
2019-05-23 16:43 ` [PATCH 2/9] KVM: selftests: Guard struct kvm_vcpu_events with __KVM_HAVE_VCPU_EVENTS Thomas Huth
2019-05-23 17:57   ` Andrew Jones
2019-05-23 16:43 ` [PATCH 3/9] kvm: selftests: aarch64: fix default vm mode Thomas Huth
2019-05-24  8:37   ` Christian Borntraeger
2019-05-23 16:43 ` [PATCH 4/9] KVM: selftests: Introduce a VM_MODE_DEFAULT macro for the default bits Thomas Huth
2019-05-23 17:20   ` Andrew Jones
2019-05-23 16:43 ` [PATCH 5/9] KVM: selftests: Align memory region addresses to 1M on s390x Thomas Huth
2019-05-23 17:40   ` Andrew Jones
2019-05-24  8:29     ` Christian Borntraeger
2019-05-24 18:17       ` Thomas Huth
2019-05-23 16:43 ` [PATCH 6/9] KVM: selftests: Add processor code for s390x Thomas Huth
2019-05-23 16:43 ` [PATCH 7/9] KVM: selftests: Add the sync_regs test " Thomas Huth
2019-05-23 16:43 ` Thomas Huth [this message]
2019-05-23 17:56   ` [PATCH 8/9] KVM: s390: Do not report unusabled IDs via KVM_CAP_MAX_VCPU_ID Andrew Jones
2019-05-24  9:13   ` Cornelia Huck
2019-05-24  9:16   ` David Hildenbrand
2019-05-28 11:00   ` Christian Borntraeger
2019-05-28 12:53     ` Cornelia Huck
2019-05-28 13:48       ` Christian Borntraeger
2019-05-23 16:43 ` [PATCH 9/9] KVM: selftests: Move kvm_create_max_vcpus test to generic code Thomas Huth
2019-05-23 17:56   ` Andrew Jones
2019-05-24  9:16   ` David Hildenbrand
2019-05-24 11:11 ` [PATCH v1 0/9] KVM selftests for s390x Christian Borntraeger
2019-05-24 12:17   ` Christian Borntraeger
2019-05-24 12:29     ` Christian Borntraeger
2019-05-24 12:36       ` David Hildenbrand
2019-05-24 12:56         ` Christian Borntraeger
2019-05-24 18:33 ` Christian Borntraeger
2019-06-04 17:19 ` Paolo Bonzini
2019-06-04 17:37   ` Christian Borntraeger

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190523164309.13345-9-thuth@redhat.com \
    --to=thuth@redhat.com \
    --cc=borntraeger@de.ibm.com \
    --cc=cohuck@redhat.com \
    --cc=david@redhat.com \
    --cc=drjones@redhat.com \
    --cc=frankja@linux.ibm.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-kselftest@vger.kernel.org \
    --cc=linux-s390@vger.kernel.org \
    --cc=pbonzini@redhat.com \
    --cc=rkrcmar@redhat.com \
    --cc=shuah@kernel.org \
    --subject='Re: [PATCH 8/9] KVM: s390: Do not report unusabled IDs via KVM_CAP_MAX_VCPU_ID' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).