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* [PATCH v3 0/4] KVM: PPC: KVM module exit fixes
@ 2022-01-25 15:57 Fabiano Rosas
  2022-01-25 15:57 ` [PATCH v3 1/4] KVM: PPC: Book3S HV: Check return value of kvmppc_radix_init Fabiano Rosas
                   ` (4 more replies)
  0 siblings, 5 replies; 6+ messages in thread
From: Fabiano Rosas @ 2022-01-25 15:57 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, npiggin, aik

changes from v2:

- patch 4: Matched module_put() to try_module_get()

v2:
https://lore.kernel.org/r/20220124220803.1011673-1-farosas@linux.ibm.com

v1:
https://lore.kernel.org/r/20211223211931.3560887-1-farosas@linux.ibm.com

Fabiano Rosas (4):
  KVM: PPC: Book3S HV: Check return value of kvmppc_radix_init
  KVM: PPC: Book3S HV: Delay setting of kvm ops
  KVM: PPC: Book3S HV: Free allocated memory if module init fails
  KVM: PPC: Decrement module refcount if init_vm fails

 arch/powerpc/kvm/book3s_hv.c | 28 ++++++++++++++++++++--------
 arch/powerpc/kvm/powerpc.c   |  9 +++++++--
 2 files changed, 27 insertions(+), 10 deletions(-)

-- 
2.34.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH v3 1/4] KVM: PPC: Book3S HV: Check return value of kvmppc_radix_init
  2022-01-25 15:57 [PATCH v3 0/4] KVM: PPC: KVM module exit fixes Fabiano Rosas
@ 2022-01-25 15:57 ` Fabiano Rosas
  2022-01-25 15:57 ` [PATCH v3 2/4] KVM: PPC: Book3S HV: Delay setting of kvm ops Fabiano Rosas
                   ` (3 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: Fabiano Rosas @ 2022-01-25 15:57 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, npiggin, aik

The return of the function is being shadowed by the call to
kvmppc_uvmem_init.

Fixes: ca9f4942670c ("KVM: PPC: Book3S HV: Support for running secure guests")
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index d1817cd9a691..3a3845f366d4 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -6138,8 +6138,11 @@ static int kvmppc_book3s_init_hv(void)
 	if (r)
 		return r;
 
-	if (kvmppc_radix_possible())
+	if (kvmppc_radix_possible()) {
 		r = kvmppc_radix_init();
+		if (r)
+			return r;
+	}
 
 	r = kvmppc_uvmem_init();
 	if (r < 0)
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH v3 2/4] KVM: PPC: Book3S HV: Delay setting of kvm ops
  2022-01-25 15:57 [PATCH v3 0/4] KVM: PPC: KVM module exit fixes Fabiano Rosas
  2022-01-25 15:57 ` [PATCH v3 1/4] KVM: PPC: Book3S HV: Check return value of kvmppc_radix_init Fabiano Rosas
@ 2022-01-25 15:57 ` Fabiano Rosas
  2022-01-25 15:57 ` [PATCH v3 3/4] KVM: PPC: Book3S HV: Free allocated memory if module init fails Fabiano Rosas
                   ` (2 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: Fabiano Rosas @ 2022-01-25 15:57 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, npiggin, aik

Delay the setting of kvm_hv_ops until after all init code has
completed. This avoids leaving the ops still accessible if the init
fails.

Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
---
 arch/powerpc/kvm/book3s_hv.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 3a3845f366d4..b9aace212599 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -6127,9 +6127,6 @@ static int kvmppc_book3s_init_hv(void)
 	}
 #endif
 
-	kvm_ops_hv.owner = THIS_MODULE;
-	kvmppc_hv_ops = &kvm_ops_hv;
-
 	init_default_hcalls();
 
 	init_vcore_lists();
@@ -6145,10 +6142,15 @@ static int kvmppc_book3s_init_hv(void)
 	}
 
 	r = kvmppc_uvmem_init();
-	if (r < 0)
+	if (r < 0) {
 		pr_err("KVM-HV: kvmppc_uvmem_init failed %d\n", r);
+		return r;
+	}
 
-	return r;
+	kvm_ops_hv.owner = THIS_MODULE;
+	kvmppc_hv_ops = &kvm_ops_hv;
+
+	return 0;
 }
 
 static void kvmppc_book3s_exit_hv(void)
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH v3 3/4] KVM: PPC: Book3S HV: Free allocated memory if module init fails
  2022-01-25 15:57 [PATCH v3 0/4] KVM: PPC: KVM module exit fixes Fabiano Rosas
  2022-01-25 15:57 ` [PATCH v3 1/4] KVM: PPC: Book3S HV: Check return value of kvmppc_radix_init Fabiano Rosas
  2022-01-25 15:57 ` [PATCH v3 2/4] KVM: PPC: Book3S HV: Delay setting of kvm ops Fabiano Rosas
@ 2022-01-25 15:57 ` Fabiano Rosas
  2022-01-25 15:57 ` [PATCH v3 4/4] KVM: PPC: Decrement module refcount if init_vm fails Fabiano Rosas
  2022-03-12 10:37 ` [PATCH v3 0/4] KVM: PPC: KVM module exit fixes Michael Ellerman
  4 siblings, 0 replies; 6+ messages in thread
From: Fabiano Rosas @ 2022-01-25 15:57 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, npiggin, aik

The module's exit function is not called when the init fails, we need
to do cleanup before returning.

Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index b9aace212599..87a49651a402 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -6104,7 +6104,7 @@ static int kvmppc_book3s_init_hv(void)
 	if (!cpu_has_feature(CPU_FTR_ARCH_300)) {
 		r = kvm_init_subcore_bitmap();
 		if (r)
-			return r;
+			goto err;
 	}
 
 	/*
@@ -6120,7 +6120,8 @@ static int kvmppc_book3s_init_hv(void)
 		np = of_find_compatible_node(NULL, NULL, "ibm,opal-intc");
 		if (!np) {
 			pr_err("KVM-HV: Cannot determine method for accessing XICS\n");
-			return -ENODEV;
+			r = -ENODEV;
+			goto err;
 		}
 		/* presence of intc confirmed - node can be dropped again */
 		of_node_put(np);
@@ -6133,12 +6134,12 @@ static int kvmppc_book3s_init_hv(void)
 
 	r = kvmppc_mmu_hv_init();
 	if (r)
-		return r;
+		goto err;
 
 	if (kvmppc_radix_possible()) {
 		r = kvmppc_radix_init();
 		if (r)
-			return r;
+			goto err;
 	}
 
 	r = kvmppc_uvmem_init();
@@ -6151,6 +6152,12 @@ static int kvmppc_book3s_init_hv(void)
 	kvmppc_hv_ops = &kvm_ops_hv;
 
 	return 0;
+
+err:
+	kvmhv_nested_exit();
+	kvmppc_radix_exit();
+
+	return r;
 }
 
 static void kvmppc_book3s_exit_hv(void)
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH v3 4/4] KVM: PPC: Decrement module refcount if init_vm fails
  2022-01-25 15:57 [PATCH v3 0/4] KVM: PPC: KVM module exit fixes Fabiano Rosas
                   ` (2 preceding siblings ...)
  2022-01-25 15:57 ` [PATCH v3 3/4] KVM: PPC: Book3S HV: Free allocated memory if module init fails Fabiano Rosas
@ 2022-01-25 15:57 ` Fabiano Rosas
  2022-03-12 10:37 ` [PATCH v3 0/4] KVM: PPC: KVM module exit fixes Michael Ellerman
  4 siblings, 0 replies; 6+ messages in thread
From: Fabiano Rosas @ 2022-01-25 15:57 UTC (permalink / raw)
  To: kvm-ppc; +Cc: linuxppc-dev, npiggin, aik

We increment the reference count for KVM-HV/PR before the call to
kvmppc_core_init_vm. If that function fails we need to decrement the
refcount.

Also remove the check on kvm_ops->owner because try_module_get can
handle a NULL module.

Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/powerpc.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 2ad0ccd202d5..a6d6d452243f 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -431,6 +431,8 @@ int kvm_arch_check_processor_compat(void *opaque)
 int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 {
 	struct kvmppc_ops *kvm_ops = NULL;
+	int r;
+
 	/*
 	 * if we have both HV and PR enabled, default is HV
 	 */
@@ -452,11 +454,14 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 	} else
 		goto err_out;
 
-	if (kvm_ops->owner && !try_module_get(kvm_ops->owner))
+	if (!try_module_get(kvm_ops->owner))
 		return -ENOENT;
 
 	kvm->arch.kvm_ops = kvm_ops;
-	return kvmppc_core_init_vm(kvm);
+	r = kvmppc_core_init_vm(kvm);
+	if (r)
+		module_put(kvm_ops->owner);
+	return r;
 err_out:
 	return -EINVAL;
 }
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH v3 0/4] KVM: PPC: KVM module exit fixes
  2022-01-25 15:57 [PATCH v3 0/4] KVM: PPC: KVM module exit fixes Fabiano Rosas
                   ` (3 preceding siblings ...)
  2022-01-25 15:57 ` [PATCH v3 4/4] KVM: PPC: Decrement module refcount if init_vm fails Fabiano Rosas
@ 2022-03-12 10:37 ` Michael Ellerman
  4 siblings, 0 replies; 6+ messages in thread
From: Michael Ellerman @ 2022-03-12 10:37 UTC (permalink / raw)
  To: Fabiano Rosas, kvm-ppc; +Cc: aik, linuxppc-dev, npiggin

On Tue, 25 Jan 2022 12:57:31 -0300, Fabiano Rosas wrote:
> changes from v2:
> 
> - patch 4: Matched module_put() to try_module_get()
> 
> v2:
> https://lore.kernel.org/r/20220124220803.1011673-1-farosas@linux.ibm.com
> 
> [...]

Applied to powerpc/topic/ppc-kvm.

[1/4] KVM: PPC: Book3S HV: Check return value of kvmppc_radix_init
      https://git.kernel.org/powerpc/c/69ab6ac380a00244575de02c406dcb9491bf3368
[2/4] KVM: PPC: Book3S HV: Delay setting of kvm ops
      https://git.kernel.org/powerpc/c/c5d0d77b45265905bba2ce6e63c9a02bbd11c43c
[3/4] KVM: PPC: Book3S HV: Free allocated memory if module init fails
      https://git.kernel.org/powerpc/c/175be7e5800e2782a7e38ee9e1b64633494c4b44
[4/4] KVM: PPC: Decrement module refcount if init_vm fails
      https://git.kernel.org/powerpc/c/4feb74aa64b35b21a4937f96d7a940adee286e5b

cheers

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2022-03-12 10:40 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2022-01-25 15:57 [PATCH v3 0/4] KVM: PPC: KVM module exit fixes Fabiano Rosas
2022-01-25 15:57 ` [PATCH v3 1/4] KVM: PPC: Book3S HV: Check return value of kvmppc_radix_init Fabiano Rosas
2022-01-25 15:57 ` [PATCH v3 2/4] KVM: PPC: Book3S HV: Delay setting of kvm ops Fabiano Rosas
2022-01-25 15:57 ` [PATCH v3 3/4] KVM: PPC: Book3S HV: Free allocated memory if module init fails Fabiano Rosas
2022-01-25 15:57 ` [PATCH v3 4/4] KVM: PPC: Decrement module refcount if init_vm fails Fabiano Rosas
2022-03-12 10:37 ` [PATCH v3 0/4] KVM: PPC: KVM module exit fixes Michael Ellerman

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