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| author | Greg Kurz <groug@kaod.org> | 2019-09-27 13:53:38 +0200 |
|---|---|---|
| committer | Paul Mackerras <paulus@ozlabs.org> | 2019-10-22 16:29:01 +1100 |
| commit | e7d71c943040c23f2fd042033d319f56e84f845b (patch) | |
| tree | 180a7725bd68112891d836c8d73fa0a6ece49b03 /arch/powerpc | |
| parent | f41c4989c8de1fa70aafe950abaf80c56a8b8712 (diff) | |
| download | lwn-e7d71c943040c23f2fd042033d319f56e84f845b.tar.gz lwn-e7d71c943040c23f2fd042033d319f56e84f845b.zip | |
KVM: PPC: Book3S HV: XIVE: Set kvm->arch.xive when VPs are allocated
If we cannot allocate the XIVE VPs in OPAL, the creation of a XIVE or
XICS-on-XIVE device is aborted as expected, but we leave kvm->arch.xive
set forever since the release method isn't called in this case. Any
subsequent tentative to create a XIVE or XICS-on-XIVE for this VM will
thus always fail (DoS). This is a problem for QEMU since it destroys
and re-creates these devices when the VM is reset: the VM would be
restricted to using the much slower emulated XIVE or XICS forever.
As an alternative to adding rollback, do not assign kvm->arch.xive before
making sure the XIVE VPs are allocated in OPAL.
Cc: stable@vger.kernel.org # v5.2
Fixes: 5422e95103cf ("KVM: PPC: Book3S HV: XIVE: Replace the 'destroy' method by a 'release' method")
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/kvm/book3s_xive.c | 11 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_xive_native.c | 2 |
2 files changed, 6 insertions, 7 deletions
diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c index a3f9c665bb5b..baa740815b3c 100644 --- a/arch/powerpc/kvm/book3s_xive.c +++ b/arch/powerpc/kvm/book3s_xive.c @@ -2005,6 +2005,10 @@ static int kvmppc_xive_create(struct kvm_device *dev, u32 type) pr_devel("Creating xive for partition\n"); + /* Already there ? */ + if (kvm->arch.xive) + return -EEXIST; + xive = kvmppc_xive_get_device(kvm, type); if (!xive) return -ENOMEM; @@ -2014,12 +2018,6 @@ static int kvmppc_xive_create(struct kvm_device *dev, u32 type) xive->kvm = kvm; mutex_init(&xive->lock); - /* Already there ? */ - if (kvm->arch.xive) - ret = -EEXIST; - else - kvm->arch.xive = xive; - /* We use the default queue size set by the host */ xive->q_order = xive_native_default_eq_shift(); if (xive->q_order < PAGE_SHIFT) @@ -2039,6 +2037,7 @@ static int kvmppc_xive_create(struct kvm_device *dev, u32 type) if (ret) return ret; + kvm->arch.xive = xive; return 0; } diff --git a/arch/powerpc/kvm/book3s_xive_native.c b/arch/powerpc/kvm/book3s_xive_native.c index 78b906ffa0d2..ebb4215baf45 100644 --- a/arch/powerpc/kvm/book3s_xive_native.c +++ b/arch/powerpc/kvm/book3s_xive_native.c @@ -1081,7 +1081,6 @@ static int kvmppc_xive_native_create(struct kvm_device *dev, u32 type) dev->private = xive; xive->dev = dev; xive->kvm = kvm; - kvm->arch.xive = xive; mutex_init(&xive->mapping_lock); mutex_init(&xive->lock); @@ -1102,6 +1101,7 @@ static int kvmppc_xive_native_create(struct kvm_device *dev, u32 type) if (ret) return ret; + kvm->arch.xive = xive; return 0; } |