* [PATCH 1/9] KVM: arm64: pvtime: steal-time is only supported when configured
2020-09-04 10:45 [GIT PULL] KVM/arm64 fixes for 5.9 Marc Zyngier
@ 2020-09-04 10:45 ` Marc Zyngier
2020-09-04 10:45 ` [PATCH 2/9] KVM: arm64: pvtime: Fix potential loss of stolen time Marc Zyngier
` (8 subsequent siblings)
9 siblings, 0 replies; 14+ messages in thread
From: Marc Zyngier @ 2020-09-04 10:45 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Andrew Jones, Gavin Shan, kvm, kernel-team, Steven Price,
Eric Auger, Alexandru Elisei, kvmarm, linux-arm-kernel
From: Andrew Jones <drjones@redhat.com>
Don't confuse the guest by saying steal-time is supported when
it hasn't been configured by userspace and won't work.
Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200804170604.42662-2-drjones@redhat.com
---
arch/arm64/kvm/pvtime.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/pvtime.c b/arch/arm64/kvm/pvtime.c
index f7b52ce1557e..c3ef4ebd6846 100644
--- a/arch/arm64/kvm/pvtime.c
+++ b/arch/arm64/kvm/pvtime.c
@@ -43,7 +43,8 @@ long kvm_hypercall_pv_features(struct kvm_vcpu *vcpu)
switch (feature) {
case ARM_SMCCC_HV_PV_TIME_FEATURES:
case ARM_SMCCC_HV_PV_TIME_ST:
- val = SMCCC_RET_SUCCESS;
+ if (vcpu->arch.steal.base != GPA_INVALID)
+ val = SMCCC_RET_SUCCESS;
break;
}
--
2.27.0
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^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH 2/9] KVM: arm64: pvtime: Fix potential loss of stolen time
2020-09-04 10:45 [GIT PULL] KVM/arm64 fixes for 5.9 Marc Zyngier
2020-09-04 10:45 ` [PATCH 1/9] KVM: arm64: pvtime: steal-time is only supported when configured Marc Zyngier
@ 2020-09-04 10:45 ` Marc Zyngier
2020-09-04 10:45 ` [PATCH 3/9] KVM: arm64: Drop type input from kvm_put_guest Marc Zyngier
` (7 subsequent siblings)
9 siblings, 0 replies; 14+ messages in thread
From: Marc Zyngier @ 2020-09-04 10:45 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Andrew Jones, Gavin Shan, kvm, kernel-team, Steven Price,
Eric Auger, Alexandru Elisei, kvmarm, linux-arm-kernel
From: Andrew Jones <drjones@redhat.com>
We should only check current->sched_info.run_delay once when
updating stolen time. Otherwise there's a chance there could
be a change between checks that we miss (preemption disabling
comes after vcpu request checks).
Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200804170604.42662-3-drjones@redhat.com
---
arch/arm64/kvm/pvtime.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kvm/pvtime.c b/arch/arm64/kvm/pvtime.c
index c3ef4ebd6846..95f9580275b1 100644
--- a/arch/arm64/kvm/pvtime.c
+++ b/arch/arm64/kvm/pvtime.c
@@ -13,6 +13,7 @@
void kvm_update_stolen_time(struct kvm_vcpu *vcpu)
{
struct kvm *kvm = vcpu->kvm;
+ u64 last_steal = vcpu->arch.steal.last_steal;
u64 steal;
__le64 steal_le;
u64 offset;
@@ -24,8 +25,8 @@ void kvm_update_stolen_time(struct kvm_vcpu *vcpu)
/* Let's do the local bookkeeping */
steal = vcpu->arch.steal.steal;
- steal += current->sched_info.run_delay - vcpu->arch.steal.last_steal;
- vcpu->arch.steal.last_steal = current->sched_info.run_delay;
+ vcpu->arch.steal.last_steal = READ_ONCE(current->sched_info.run_delay);
+ steal += vcpu->arch.steal.last_steal - last_steal;
vcpu->arch.steal.steal = steal;
steal_le = cpu_to_le64(steal);
--
2.27.0
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^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH 3/9] KVM: arm64: Drop type input from kvm_put_guest
2020-09-04 10:45 [GIT PULL] KVM/arm64 fixes for 5.9 Marc Zyngier
2020-09-04 10:45 ` [PATCH 1/9] KVM: arm64: pvtime: steal-time is only supported when configured Marc Zyngier
2020-09-04 10:45 ` [PATCH 2/9] KVM: arm64: pvtime: Fix potential loss of stolen time Marc Zyngier
@ 2020-09-04 10:45 ` Marc Zyngier
2020-09-04 10:45 ` [PATCH 4/9] KVM: arm64: pvtime: Fix stolen time accounting across migration Marc Zyngier
` (6 subsequent siblings)
9 siblings, 0 replies; 14+ messages in thread
From: Marc Zyngier @ 2020-09-04 10:45 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Andrew Jones, Gavin Shan, kvm, kernel-team, Steven Price,
Eric Auger, Alexandru Elisei, kvmarm, linux-arm-kernel
From: Andrew Jones <drjones@redhat.com>
We can use typeof() to avoid the need for the type input.
Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200804170604.42662-4-drjones@redhat.com
---
arch/arm64/kvm/pvtime.c | 2 +-
include/linux/kvm_host.h | 11 ++++++-----
2 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/kvm/pvtime.c b/arch/arm64/kvm/pvtime.c
index 95f9580275b1..241ded7ee0ad 100644
--- a/arch/arm64/kvm/pvtime.c
+++ b/arch/arm64/kvm/pvtime.c
@@ -32,7 +32,7 @@ void kvm_update_stolen_time(struct kvm_vcpu *vcpu)
steal_le = cpu_to_le64(steal);
idx = srcu_read_lock(&kvm->srcu);
offset = offsetof(struct pvclock_vcpu_stolen_time, stolen_time);
- kvm_put_guest(kvm, base + offset, steal_le, u64);
+ kvm_put_guest(kvm, base + offset, steal_le);
srcu_read_unlock(&kvm->srcu, idx);
}
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index a23076765b4c..84371fb06209 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -749,25 +749,26 @@ int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
gpa_t gpa, unsigned long len);
-#define __kvm_put_guest(kvm, gfn, offset, value, type) \
+#define __kvm_put_guest(kvm, gfn, offset, v) \
({ \
unsigned long __addr = gfn_to_hva(kvm, gfn); \
- type __user *__uaddr = (type __user *)(__addr + offset); \
+ typeof(v) __user *__uaddr = (typeof(__uaddr))(__addr + offset); \
int __ret = -EFAULT; \
\
if (!kvm_is_error_hva(__addr)) \
- __ret = put_user(value, __uaddr); \
+ __ret = put_user(v, __uaddr); \
if (!__ret) \
mark_page_dirty(kvm, gfn); \
__ret; \
})
-#define kvm_put_guest(kvm, gpa, value, type) \
+#define kvm_put_guest(kvm, gpa, v) \
({ \
gpa_t __gpa = gpa; \
struct kvm *__kvm = kvm; \
+ \
__kvm_put_guest(__kvm, __gpa >> PAGE_SHIFT, \
- offset_in_page(__gpa), (value), type); \
+ offset_in_page(__gpa), v); \
})
int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len);
--
2.27.0
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^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH 4/9] KVM: arm64: pvtime: Fix stolen time accounting across migration
2020-09-04 10:45 [GIT PULL] KVM/arm64 fixes for 5.9 Marc Zyngier
` (2 preceding siblings ...)
2020-09-04 10:45 ` [PATCH 3/9] KVM: arm64: Drop type input from kvm_put_guest Marc Zyngier
@ 2020-09-04 10:45 ` Marc Zyngier
2020-09-04 10:45 ` [PATCH 5/9] KVM: Documentation: Minor fixups Marc Zyngier
` (5 subsequent siblings)
9 siblings, 0 replies; 14+ messages in thread
From: Marc Zyngier @ 2020-09-04 10:45 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Andrew Jones, Gavin Shan, kvm, kernel-team, Steven Price,
Eric Auger, Alexandru Elisei, kvmarm, linux-arm-kernel
From: Andrew Jones <drjones@redhat.com>
When updating the stolen time we should always read the current
stolen time from the user provided memory, not from a kernel
cache. If we use a cache then we'll end up resetting stolen time
to zero on the first update after migration.
Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200804170604.42662-5-drjones@redhat.com
---
arch/arm64/include/asm/kvm_host.h | 1 -
arch/arm64/kvm/pvtime.c | 23 +++++++++--------------
include/linux/kvm_host.h | 20 ++++++++++++++++++++
3 files changed, 29 insertions(+), 15 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 65568b23868a..dd9c3b25aa1e 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -368,7 +368,6 @@ struct kvm_vcpu_arch {
/* Guest PV state */
struct {
- u64 steal;
u64 last_steal;
gpa_t base;
} steal;
diff --git a/arch/arm64/kvm/pvtime.c b/arch/arm64/kvm/pvtime.c
index 241ded7ee0ad..75234321d896 100644
--- a/arch/arm64/kvm/pvtime.c
+++ b/arch/arm64/kvm/pvtime.c
@@ -13,26 +13,22 @@
void kvm_update_stolen_time(struct kvm_vcpu *vcpu)
{
struct kvm *kvm = vcpu->kvm;
+ u64 base = vcpu->arch.steal.base;
u64 last_steal = vcpu->arch.steal.last_steal;
- u64 steal;
- __le64 steal_le;
- u64 offset;
+ u64 offset = offsetof(struct pvclock_vcpu_stolen_time, stolen_time);
+ u64 steal = 0;
int idx;
- u64 base = vcpu->arch.steal.base;
if (base == GPA_INVALID)
return;
- /* Let's do the local bookkeeping */
- steal = vcpu->arch.steal.steal;
- vcpu->arch.steal.last_steal = READ_ONCE(current->sched_info.run_delay);
- steal += vcpu->arch.steal.last_steal - last_steal;
- vcpu->arch.steal.steal = steal;
-
- steal_le = cpu_to_le64(steal);
idx = srcu_read_lock(&kvm->srcu);
- offset = offsetof(struct pvclock_vcpu_stolen_time, stolen_time);
- kvm_put_guest(kvm, base + offset, steal_le);
+ if (!kvm_get_guest(kvm, base + offset, steal)) {
+ steal = le64_to_cpu(steal);
+ vcpu->arch.steal.last_steal = READ_ONCE(current->sched_info.run_delay);
+ steal += vcpu->arch.steal.last_steal - last_steal;
+ kvm_put_guest(kvm, base + offset, cpu_to_le64(steal));
+ }
srcu_read_unlock(&kvm->srcu, idx);
}
@@ -66,7 +62,6 @@ gpa_t kvm_init_stolen_time(struct kvm_vcpu *vcpu)
* Start counting stolen time from the time the guest requests
* the feature enabled.
*/
- vcpu->arch.steal.steal = 0;
vcpu->arch.steal.last_steal = current->sched_info.run_delay;
idx = srcu_read_lock(&kvm->srcu);
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 84371fb06209..05e3c2fb3ef7 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -749,6 +749,26 @@ int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
gpa_t gpa, unsigned long len);
+#define __kvm_get_guest(kvm, gfn, offset, v) \
+({ \
+ unsigned long __addr = gfn_to_hva(kvm, gfn); \
+ typeof(v) __user *__uaddr = (typeof(__uaddr))(__addr + offset); \
+ int __ret = -EFAULT; \
+ \
+ if (!kvm_is_error_hva(__addr)) \
+ __ret = get_user(v, __uaddr); \
+ __ret; \
+})
+
+#define kvm_get_guest(kvm, gpa, v) \
+({ \
+ gpa_t __gpa = gpa; \
+ struct kvm *__kvm = kvm; \
+ \
+ __kvm_get_guest(__kvm, __gpa >> PAGE_SHIFT, \
+ offset_in_page(__gpa), v); \
+})
+
#define __kvm_put_guest(kvm, gfn, offset, v) \
({ \
unsigned long __addr = gfn_to_hva(kvm, gfn); \
--
2.27.0
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http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH 5/9] KVM: Documentation: Minor fixups
2020-09-04 10:45 [GIT PULL] KVM/arm64 fixes for 5.9 Marc Zyngier
` (3 preceding siblings ...)
2020-09-04 10:45 ` [PATCH 4/9] KVM: arm64: pvtime: Fix stolen time accounting across migration Marc Zyngier
@ 2020-09-04 10:45 ` Marc Zyngier
2020-09-04 10:45 ` [PATCH 6/9] arm64/x86: KVM: Introduce steal-time cap Marc Zyngier
` (4 subsequent siblings)
9 siblings, 0 replies; 14+ messages in thread
From: Marc Zyngier @ 2020-09-04 10:45 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Andrew Jones, Gavin Shan, kvm, kernel-team, Steven Price,
Eric Auger, Alexandru Elisei, kvmarm, linux-arm-kernel
From: Andrew Jones <drjones@redhat.com>
In preparation for documenting a new capability let's fix up the
formatting of the current ones.
Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20200804170604.42662-6-drjones@redhat.com
---
Documentation/virt/kvm/api.rst | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index eb3a1316f03e..49af23d2b462 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -6130,7 +6130,7 @@ HvCallSendSyntheticClusterIpi, HvCallSendSyntheticClusterIpiEx.
8.21 KVM_CAP_HYPERV_DIRECT_TLBFLUSH
-----------------------------------
-:Architecture: x86
+:Architectures: x86
This capability indicates that KVM running on top of Hyper-V hypervisor
enables Direct TLB flush for its guests meaning that TLB flush
@@ -6143,16 +6143,17 @@ in CPUID and only exposes Hyper-V identification. In this case, guest
thinks it's running on Hyper-V and only use Hyper-V hypercalls.
8.22 KVM_CAP_S390_VCPU_RESETS
+-----------------------------
-Architectures: s390
+:Architectures: s390
This capability indicates that the KVM_S390_NORMAL_RESET and
KVM_S390_CLEAR_RESET ioctls are available.
8.23 KVM_CAP_S390_PROTECTED
+---------------------------
-Architecture: s390
-
+:Architectures: s390
This capability indicates that the Ultravisor has been initialized and
KVM can therefore start protected VMs.
--
2.27.0
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^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH 6/9] arm64/x86: KVM: Introduce steal-time cap
2020-09-04 10:45 [GIT PULL] KVM/arm64 fixes for 5.9 Marc Zyngier
` (4 preceding siblings ...)
2020-09-04 10:45 ` [PATCH 5/9] KVM: Documentation: Minor fixups Marc Zyngier
@ 2020-09-04 10:45 ` Marc Zyngier
2020-09-04 10:45 ` [PATCH 7/9] KVM: arm64: Do not try to map PUDs when they are folded into PMD Marc Zyngier
` (3 subsequent siblings)
9 siblings, 0 replies; 14+ messages in thread
From: Marc Zyngier @ 2020-09-04 10:45 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Andrew Jones, Gavin Shan, kvm, kernel-team, Steven Price,
Eric Auger, Alexandru Elisei, kvmarm, linux-arm-kernel
From: Andrew Jones <drjones@redhat.com>
arm64 requires a vcpu fd (KVM_HAS_DEVICE_ATTR vcpu ioctl) to probe
support for steal-time. However this is unnecessary, as only a KVM
fd is required, and it complicates userspace (userspace may prefer
delaying vcpu creation until after feature probing). Introduce a cap
that can be checked instead. While x86 can already probe steal-time
support with a kvm fd (KVM_GET_SUPPORTED_CPUID), we add the cap there
too for consistency.
Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20200804170604.42662-7-drjones@redhat.com
---
Documentation/virt/kvm/api.rst | 13 +++++++++++++
arch/arm64/include/asm/kvm_host.h | 1 +
arch/arm64/kvm/arm.c | 3 +++
arch/arm64/kvm/pvtime.c | 2 +-
arch/x86/kvm/x86.c | 3 +++
include/uapi/linux/kvm.h | 1 +
6 files changed, 22 insertions(+), 1 deletion(-)
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 49af23d2b462..d2b733dc7892 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -6160,3 +6160,16 @@ KVM can therefore start protected VMs.
This capability governs the KVM_S390_PV_COMMAND ioctl and the
KVM_MP_STATE_LOAD MP_STATE. KVM_SET_MP_STATE can fail for protected
guests when the state change is invalid.
+
+8.24 KVM_CAP_STEAL_TIME
+-----------------------
+
+:Architectures: arm64, x86
+
+This capability indicates that KVM supports steal time accounting.
+When steal time accounting is supported it may be enabled with
+architecture-specific interfaces. This capability and the architecture-
+specific interfaces must be consistent, i.e. if one says the feature
+is supported, than the other should as well and vice versa. For arm64
+see Documentation/virt/kvm/devices/vcpu.rst "KVM_ARM_VCPU_PVTIME_CTRL".
+For x86 see Documentation/virt/kvm/msr.rst "MSR_KVM_STEAL_TIME".
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index dd9c3b25aa1e..af4989a25bb7 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -543,6 +543,7 @@ long kvm_hypercall_pv_features(struct kvm_vcpu *vcpu);
gpa_t kvm_init_stolen_time(struct kvm_vcpu *vcpu);
void kvm_update_stolen_time(struct kvm_vcpu *vcpu);
+bool kvm_arm_pvtime_supported(void);
int kvm_arm_pvtime_set_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr);
int kvm_arm_pvtime_get_attr(struct kvm_vcpu *vcpu,
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 691d21e4c717..57876b0b870b 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -206,6 +206,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
*/
r = 1;
break;
+ case KVM_CAP_STEAL_TIME:
+ r = kvm_arm_pvtime_supported();
+ break;
default:
r = kvm_arch_vm_ioctl_check_extension(kvm, ext);
break;
diff --git a/arch/arm64/kvm/pvtime.c b/arch/arm64/kvm/pvtime.c
index 75234321d896..920ac43077ad 100644
--- a/arch/arm64/kvm/pvtime.c
+++ b/arch/arm64/kvm/pvtime.c
@@ -71,7 +71,7 @@ gpa_t kvm_init_stolen_time(struct kvm_vcpu *vcpu)
return base;
}
-static bool kvm_arm_pvtime_supported(void)
+bool kvm_arm_pvtime_supported(void)
{
return !!sched_info_on();
}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 599d73206299..c44d3a73b8eb 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3581,6 +3581,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_SMALLER_MAXPHYADDR:
r = (int) allow_smaller_maxphyaddr;
break;
+ case KVM_CAP_STEAL_TIME:
+ r = sched_info_on();
+ break;
default:
break;
}
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index f6d86033c4fa..3d8023474f2a 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1035,6 +1035,7 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_LAST_CPU 184
#define KVM_CAP_SMALLER_MAXPHYADDR 185
#define KVM_CAP_S390_DIAG318 186
+#define KVM_CAP_STEAL_TIME 187
#ifdef KVM_CAP_IRQ_ROUTING
--
2.27.0
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^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH 7/9] KVM: arm64: Do not try to map PUDs when they are folded into PMD
2020-09-04 10:45 [GIT PULL] KVM/arm64 fixes for 5.9 Marc Zyngier
` (5 preceding siblings ...)
2020-09-04 10:45 ` [PATCH 6/9] arm64/x86: KVM: Introduce steal-time cap Marc Zyngier
@ 2020-09-04 10:45 ` Marc Zyngier
2020-09-09 3:23 ` Punit Agrawal
2020-09-04 10:45 ` [PATCH 8/9] KVM: arm64: Fix address truncation in traces Marc Zyngier
` (2 subsequent siblings)
9 siblings, 1 reply; 14+ messages in thread
From: Marc Zyngier @ 2020-09-04 10:45 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Andrew Jones, Gavin Shan, kvm, kernel-team, stable, Steven Price,
Eric Auger, Alexandru Elisei, kvmarm, linux-arm-kernel
For the obscure cases where PMD and PUD are the same size
(64kB pages with 42bit VA, for example, which results in only
two levels of page tables), we can't map anything as a PUD,
because there is... erm... no PUD to speak of. Everything is
either a PMD or a PTE.
So let's only try and map a PUD when its size is different from
that of a PMD.
Cc: stable@vger.kernel.org
Fixes: b8e0ba7c8bea ("KVM: arm64: Add support for creating PUD hugepages at stage 2")
Reported-by: Gavin Shan <gshan@redhat.com>
Reported-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Tested-by: Gavin Shan <gshan@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/mmu.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 0121ef2c7c8d..16b8660ddbcc 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1964,7 +1964,12 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
(fault_status == FSC_PERM &&
stage2_is_exec(mmu, fault_ipa, vma_pagesize));
- if (vma_pagesize == PUD_SIZE) {
+ /*
+ * If PUD_SIZE == PMD_SIZE, there is no real PUD level, and
+ * all we have is a 2-level page table. Trying to map a PUD in
+ * this case would be fatally wrong.
+ */
+ if (PUD_SIZE != PMD_SIZE && vma_pagesize == PUD_SIZE) {
pud_t new_pud = kvm_pfn_pud(pfn, mem_type);
new_pud = kvm_pud_mkhuge(new_pud);
--
2.27.0
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^ permalink raw reply related [flat|nested] 14+ messages in thread* Re: [PATCH 7/9] KVM: arm64: Do not try to map PUDs when they are folded into PMD
2020-09-04 10:45 ` [PATCH 7/9] KVM: arm64: Do not try to map PUDs when they are folded into PMD Marc Zyngier
@ 2020-09-09 3:23 ` Punit Agrawal
0 siblings, 0 replies; 14+ messages in thread
From: Punit Agrawal @ 2020-09-09 3:23 UTC (permalink / raw)
To: Marc Zyngier
Cc: Andrew Jones, Gavin Shan, kvm, kernel-team, stable, Steven Price,
Eric Auger, Paolo Bonzini, Alexandru Elisei, kvmarm,
linux-arm-kernel
Hi Marc,
Noticed this patch while catching up with the lists.
Marc Zyngier <maz@kernel.org> writes:
> For the obscure cases where PMD and PUD are the same size
> (64kB pages with 42bit VA, for example, which results in only
> two levels of page tables), we can't map anything as a PUD,
> because there is... erm... no PUD to speak of. Everything is
> either a PMD or a PTE.
>
> So let's only try and map a PUD when its size is different from
> that of a PMD.
>
> Cc: stable@vger.kernel.org
> Fixes: b8e0ba7c8bea ("KVM: arm64: Add support for creating PUD hugepages at stage 2")
> Reported-by: Gavin Shan <gshan@redhat.com>
> Reported-by: Eric Auger <eric.auger@redhat.com>
> Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
> Reviewed-by: Gavin Shan <gshan@redhat.com>
> Tested-by: Gavin Shan <gshan@redhat.com>
> Tested-by: Eric Auger <eric.auger@redhat.com>
> Tested-by: Alexandru Elisei <alexandru.elisei@arm.com>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> arch/arm64/kvm/mmu.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
> index 0121ef2c7c8d..16b8660ddbcc 100644
> --- a/arch/arm64/kvm/mmu.c
> +++ b/arch/arm64/kvm/mmu.c
> @@ -1964,7 +1964,12 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
> (fault_status == FSC_PERM &&
> stage2_is_exec(mmu, fault_ipa, vma_pagesize));
>
> - if (vma_pagesize == PUD_SIZE) {
> + /*
> + * If PUD_SIZE == PMD_SIZE, there is no real PUD level, and
> + * all we have is a 2-level page table. Trying to map a PUD in
> + * this case would be fatally wrong.
> + */
> + if (PUD_SIZE != PMD_SIZE && vma_pagesize == PUD_SIZE) {
> pud_t new_pud = kvm_pfn_pud(pfn, mem_type);
>
> new_pud = kvm_pud_mkhuge(new_pud);
Good catch!
Missed the 64kb / 42b VA case while adding the initial support.
Thanks for fixing it.
Punit
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^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH 8/9] KVM: arm64: Fix address truncation in traces
2020-09-04 10:45 [GIT PULL] KVM/arm64 fixes for 5.9 Marc Zyngier
` (6 preceding siblings ...)
2020-09-04 10:45 ` [PATCH 7/9] KVM: arm64: Do not try to map PUDs when they are folded into PMD Marc Zyngier
@ 2020-09-04 10:45 ` Marc Zyngier
2020-09-04 10:45 ` [PATCH 9/9] KVM: arm64: Update page shift if stage 2 block mapping not supported Marc Zyngier
2020-09-09 15:20 ` [GIT PULL] KVM/arm64 fixes for 5.9 Paolo Bonzini
9 siblings, 0 replies; 14+ messages in thread
From: Marc Zyngier @ 2020-09-04 10:45 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Andrew Jones, Gavin Shan, kvm, kernel-team, Steven Price,
Eric Auger, Alexandru Elisei, kvmarm, linux-arm-kernel
Owing to their ARMv7 origins, the trace events are truncating most
address values to 32bits. That's not really helpful.
Expand the printing of such values to their full glory.
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/trace_arm.h | 16 ++++++++--------
arch/arm64/kvm/trace_handle_exit.h | 6 +++---
2 files changed, 11 insertions(+), 11 deletions(-)
diff --git a/arch/arm64/kvm/trace_arm.h b/arch/arm64/kvm/trace_arm.h
index 4691053c5ee4..ff0444352bba 100644
--- a/arch/arm64/kvm/trace_arm.h
+++ b/arch/arm64/kvm/trace_arm.h
@@ -23,7 +23,7 @@ TRACE_EVENT(kvm_entry,
__entry->vcpu_pc = vcpu_pc;
),
- TP_printk("PC: 0x%08lx", __entry->vcpu_pc)
+ TP_printk("PC: 0x%016lx", __entry->vcpu_pc)
);
TRACE_EVENT(kvm_exit,
@@ -42,7 +42,7 @@ TRACE_EVENT(kvm_exit,
__entry->vcpu_pc = vcpu_pc;
),
- TP_printk("%s: HSR_EC: 0x%04x (%s), PC: 0x%08lx",
+ TP_printk("%s: HSR_EC: 0x%04x (%s), PC: 0x%016lx",
__print_symbolic(__entry->ret, kvm_arm_exception_type),
__entry->esr_ec,
__print_symbolic(__entry->esr_ec, kvm_arm_exception_class),
@@ -69,7 +69,7 @@ TRACE_EVENT(kvm_guest_fault,
__entry->ipa = ipa;
),
- TP_printk("ipa %#llx, hsr %#08lx, hxfar %#08lx, pc %#08lx",
+ TP_printk("ipa %#llx, hsr %#08lx, hxfar %#08lx, pc %#016lx",
__entry->ipa, __entry->hsr,
__entry->hxfar, __entry->vcpu_pc)
);
@@ -131,7 +131,7 @@ TRACE_EVENT(kvm_mmio_emulate,
__entry->cpsr = cpsr;
),
- TP_printk("Emulate MMIO at: 0x%08lx (instr: %08lx, cpsr: %08lx)",
+ TP_printk("Emulate MMIO at: 0x%016lx (instr: %08lx, cpsr: %08lx)",
__entry->vcpu_pc, __entry->instr, __entry->cpsr)
);
@@ -149,7 +149,7 @@ TRACE_EVENT(kvm_unmap_hva_range,
__entry->end = end;
),
- TP_printk("mmu notifier unmap range: %#08lx -- %#08lx",
+ TP_printk("mmu notifier unmap range: %#016lx -- %#016lx",
__entry->start, __entry->end)
);
@@ -165,7 +165,7 @@ TRACE_EVENT(kvm_set_spte_hva,
__entry->hva = hva;
),
- TP_printk("mmu notifier set pte hva: %#08lx", __entry->hva)
+ TP_printk("mmu notifier set pte hva: %#016lx", __entry->hva)
);
TRACE_EVENT(kvm_age_hva,
@@ -182,7 +182,7 @@ TRACE_EVENT(kvm_age_hva,
__entry->end = end;
),
- TP_printk("mmu notifier age hva: %#08lx -- %#08lx",
+ TP_printk("mmu notifier age hva: %#016lx -- %#016lx",
__entry->start, __entry->end)
);
@@ -198,7 +198,7 @@ TRACE_EVENT(kvm_test_age_hva,
__entry->hva = hva;
),
- TP_printk("mmu notifier test age hva: %#08lx", __entry->hva)
+ TP_printk("mmu notifier test age hva: %#016lx", __entry->hva)
);
TRACE_EVENT(kvm_set_way_flush,
diff --git a/arch/arm64/kvm/trace_handle_exit.h b/arch/arm64/kvm/trace_handle_exit.h
index 2c56d1e0f5bd..8d78acc4fba7 100644
--- a/arch/arm64/kvm/trace_handle_exit.h
+++ b/arch/arm64/kvm/trace_handle_exit.h
@@ -22,7 +22,7 @@ TRACE_EVENT(kvm_wfx_arm64,
__entry->is_wfe = is_wfe;
),
- TP_printk("guest executed wf%c at: 0x%08lx",
+ TP_printk("guest executed wf%c at: 0x%016lx",
__entry->is_wfe ? 'e' : 'i', __entry->vcpu_pc)
);
@@ -42,7 +42,7 @@ TRACE_EVENT(kvm_hvc_arm64,
__entry->imm = imm;
),
- TP_printk("HVC at 0x%08lx (r0: 0x%08lx, imm: 0x%lx)",
+ TP_printk("HVC at 0x%016lx (r0: 0x%016lx, imm: 0x%lx)",
__entry->vcpu_pc, __entry->r0, __entry->imm)
);
@@ -135,7 +135,7 @@ TRACE_EVENT(trap_reg,
__entry->write_value = write_value;
),
- TP_printk("%s %s reg %d (0x%08llx)", __entry->fn, __entry->is_write?"write to":"read from", __entry->reg, __entry->write_value)
+ TP_printk("%s %s reg %d (0x%016llx)", __entry->fn, __entry->is_write?"write to":"read from", __entry->reg, __entry->write_value)
);
TRACE_EVENT(kvm_handle_sys_reg,
--
2.27.0
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^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH 9/9] KVM: arm64: Update page shift if stage 2 block mapping not supported
2020-09-04 10:45 [GIT PULL] KVM/arm64 fixes for 5.9 Marc Zyngier
` (7 preceding siblings ...)
2020-09-04 10:45 ` [PATCH 8/9] KVM: arm64: Fix address truncation in traces Marc Zyngier
@ 2020-09-04 10:45 ` Marc Zyngier
2020-09-09 15:20 ` [GIT PULL] KVM/arm64 fixes for 5.9 Paolo Bonzini
9 siblings, 0 replies; 14+ messages in thread
From: Marc Zyngier @ 2020-09-04 10:45 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Andrew Jones, Gavin Shan, kvm, kernel-team, Steven Price,
Eric Auger, Alexandru Elisei, kvmarm, linux-arm-kernel
From: Alexandru Elisei <alexandru.elisei@arm.com>
Commit 196f878a7ac2e (" KVM: arm/arm64: Signal SIGBUS when stage2 discovers
hwpoison memory") modifies user_mem_abort() to send a SIGBUS signal when
the fault IPA maps to a hwpoisoned page. Commit 1559b7583ff6 ("KVM:
arm/arm64: Re-check VMA on detecting a poisoned page") changed
kvm_send_hwpoison_signal() to use the page shift instead of the VMA because
at that point the code had already released the mmap lock, which means
userspace could have modified the VMA.
If userspace uses hugetlbfs for the VM memory, user_mem_abort() tries to
map the guest fault IPA using block mappings in stage 2. That is not always
possible, if, for example, userspace uses dirty page logging for the VM.
Update the page shift appropriately in those cases when we downgrade the
stage 2 entry from a block mapping to a page.
Fixes: 1559b7583ff6 ("KVM: arm/arm64: Re-check VMA on detecting a poisoned page")
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Link: https://lore.kernel.org/r/20200901133357.52640-2-alexandru.elisei@arm.com
---
arch/arm64/kvm/mmu.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 16b8660ddbcc..f58d657a898d 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1871,6 +1871,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
!fault_supports_stage2_huge_mapping(memslot, hva, vma_pagesize)) {
force_pte = true;
vma_pagesize = PAGE_SIZE;
+ vma_shift = PAGE_SHIFT;
}
/*
--
2.27.0
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^ permalink raw reply related [flat|nested] 14+ messages in thread* Re: [GIT PULL] KVM/arm64 fixes for 5.9
2020-09-04 10:45 [GIT PULL] KVM/arm64 fixes for 5.9 Marc Zyngier
` (8 preceding siblings ...)
2020-09-04 10:45 ` [PATCH 9/9] KVM: arm64: Update page shift if stage 2 block mapping not supported Marc Zyngier
@ 2020-09-09 15:20 ` Paolo Bonzini
2020-09-09 17:15 ` Marc Zyngier
9 siblings, 1 reply; 14+ messages in thread
From: Paolo Bonzini @ 2020-09-09 15:20 UTC (permalink / raw)
To: Marc Zyngier
Cc: Andrew Jones, Gavin Shan, kvm, kernel-team, Steven Price,
Eric Auger, Alexandru Elisei, kvmarm, linux-arm-kernel
On 04/09/20 12:45, Marc Zyngier wrote:
> Hi Paolo,
>
> Here's a bunch of fixes for 5.9. The gist of it is the stolen time
> rework from Andrew, but we also have a couple of MM fixes that have
> surfaced as people have started to use hugetlbfs in anger.
Hi Marc,
I'll get to this next Friday.
Paolo
> Please pull,
>
> M.
>
> The following changes since commit 9123e3a74ec7b934a4a099e98af6a61c2f80bbf5:
>
> Linux 5.9-rc1 (2020-08-16 13:04:57 -0700)
>
> are available in the Git repository at:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm.git tags/kvmarm-fixes-5.9-1
>
> for you to fetch changes up to 7b75cd5128421c673153efb1236705696a1a9812:
>
> KVM: arm64: Update page shift if stage 2 block mapping not supported (2020-09-04 10:53:48 +0100)
>
> ----------------------------------------------------------------
> KVM/arm64 fixes for Linux 5.9, take #1
>
> - Multiple stolen time fixes, with a new capability to match x86
> - Fix for hugetlbfs mappings when PUD and PMD are the same level
> - Fix for hugetlbfs mappings when PTE mappings are enforced
> (dirty logging, for example)
> - Fix tracing output of 64bit values
>
> ----------------------------------------------------------------
> Alexandru Elisei (1):
> KVM: arm64: Update page shift if stage 2 block mapping not supported
>
> Andrew Jones (6):
> KVM: arm64: pvtime: steal-time is only supported when configured
> KVM: arm64: pvtime: Fix potential loss of stolen time
> KVM: arm64: Drop type input from kvm_put_guest
> KVM: arm64: pvtime: Fix stolen time accounting across migration
> KVM: Documentation: Minor fixups
> arm64/x86: KVM: Introduce steal-time cap
>
> Marc Zyngier (2):
> KVM: arm64: Do not try to map PUDs when they are folded into PMD
> KVM: arm64: Fix address truncation in traces
>
> Documentation/virt/kvm/api.rst | 22 ++++++++++++++++++----
> arch/arm64/include/asm/kvm_host.h | 2 +-
> arch/arm64/kvm/arm.c | 3 +++
> arch/arm64/kvm/mmu.c | 8 +++++++-
> arch/arm64/kvm/pvtime.c | 29 +++++++++++++----------------
> arch/arm64/kvm/trace_arm.h | 16 ++++++++--------
> arch/arm64/kvm/trace_handle_exit.h | 6 +++---
> arch/x86/kvm/x86.c | 3 +++
> include/linux/kvm_host.h | 31 ++++++++++++++++++++++++++-----
> include/uapi/linux/kvm.h | 1 +
> 10 files changed, 83 insertions(+), 38 deletions(-)
>
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^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [GIT PULL] KVM/arm64 fixes for 5.9
2020-09-09 15:20 ` [GIT PULL] KVM/arm64 fixes for 5.9 Paolo Bonzini
@ 2020-09-09 17:15 ` Marc Zyngier
2020-09-09 17:20 ` Paolo Bonzini
0 siblings, 1 reply; 14+ messages in thread
From: Marc Zyngier @ 2020-09-09 17:15 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Andrew Jones, Gavin Shan, kvm, kernel-team, Steven Price,
Eric Auger, Alexandru Elisei, kvmarm, linux-arm-kernel
On 2020-09-09 16:20, Paolo Bonzini wrote:
> On 04/09/20 12:45, Marc Zyngier wrote:
>> Hi Paolo,
>>
>> Here's a bunch of fixes for 5.9. The gist of it is the stolen time
>> rework from Andrew, but we also have a couple of MM fixes that have
>> surfaced as people have started to use hugetlbfs in anger.
>
> Hi Marc,
>
> I'll get to this next Friday.
Thanks. I may have another one for you by then though...
M.
--
Jazz is not dead. It just smells funny...
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^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [GIT PULL] KVM/arm64 fixes for 5.9
2020-09-09 17:15 ` Marc Zyngier
@ 2020-09-09 17:20 ` Paolo Bonzini
0 siblings, 0 replies; 14+ messages in thread
From: Paolo Bonzini @ 2020-09-09 17:20 UTC (permalink / raw)
To: Marc Zyngier
Cc: Andrew Jones, Gavin Shan, kvm, kernel-team, Steven Price,
Eric Auger, Alexandru Elisei, kvmarm, linux-arm-kernel
On 09/09/20 19:15, Marc Zyngier wrote:
> On 2020-09-09 16:20, Paolo Bonzini wrote:
>> On 04/09/20 12:45, Marc Zyngier wrote:
>>> Hi Paolo,
>>>
>>> Here's a bunch of fixes for 5.9. The gist of it is the stolen time
>>> rework from Andrew, but we also have a couple of MM fixes that have
>>> surfaced as people have started to use hugetlbfs in anger.
>>
>> Hi Marc,
>>
>> I'll get to this next Friday.
>
> Thanks. I may have another one for you by then though...
Sure, you can choose whether to send a separate tag or update this one.
Paolo
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^ permalink raw reply [flat|nested] 14+ messages in thread