* [PATCH v2 1/3] KVM: arm64: Bump guest PSCI version to 1.1
2022-02-21 15:35 [PATCH v2 0/3] Plumb PSCI SYSTEM_RESET2 call for guests Will Deacon
@ 2022-02-21 15:35 ` Will Deacon
2022-02-21 15:35 ` [PATCH v2 2/3] KVM: arm64: Expose PSCI SYSTEM_RESET2 call to the guest Will Deacon
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Will Deacon @ 2022-02-21 15:35 UTC (permalink / raw)
To: kvmarm
Cc: linux-arm-kernel, Will Deacon, Marc Zyngier, James Morse,
Alexandru Elisei, Suzuki K Poulose
Expose PSCI version v1.1 to the guest by default. The only difference
for now is that an updated version number is reported by PSCI_VERSION.
Cc: Marc Zyngier <maz@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/kvm/psci.c | 12 +++++++++---
include/kvm/arm_psci.h | 3 ++-
2 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c
index 3eae32876897..70d07477e712 100644
--- a/arch/arm64/kvm/psci.c
+++ b/arch/arm64/kvm/psci.c
@@ -305,16 +305,19 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
return ret;
}
-static int kvm_psci_1_0_call(struct kvm_vcpu *vcpu)
+static int kvm_psci_1_x_call(struct kvm_vcpu *vcpu, u32 minor)
{
u32 psci_fn = smccc_get_function(vcpu);
u32 feature;
unsigned long val;
int ret = 1;
+ if (minor > 1)
+ return -EINVAL;
+
switch(psci_fn) {
case PSCI_0_2_FN_PSCI_VERSION:
- val = KVM_ARM_PSCI_1_0;
+ val = minor == 0 ? KVM_ARM_PSCI_1_0 : KVM_ARM_PSCI_1_1;
break;
case PSCI_1_0_FN_PSCI_FEATURES:
feature = smccc_get_arg1(vcpu);
@@ -393,8 +396,10 @@ static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
int kvm_psci_call(struct kvm_vcpu *vcpu)
{
switch (kvm_psci_version(vcpu, vcpu->kvm)) {
+ case KVM_ARM_PSCI_1_1:
+ return kvm_psci_1_x_call(vcpu, 1);
case KVM_ARM_PSCI_1_0:
- return kvm_psci_1_0_call(vcpu);
+ return kvm_psci_1_x_call(vcpu, 0);
case KVM_ARM_PSCI_0_2:
return kvm_psci_0_2_call(vcpu);
case KVM_ARM_PSCI_0_1:
@@ -511,6 +516,7 @@ int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
return 0;
case KVM_ARM_PSCI_0_2:
case KVM_ARM_PSCI_1_0:
+ case KVM_ARM_PSCI_1_1:
if (!wants_02)
return -EINVAL;
vcpu->kvm->arch.psci_version = val;
diff --git a/include/kvm/arm_psci.h b/include/kvm/arm_psci.h
index 5b58bd2fe088..4a1003323a0c 100644
--- a/include/kvm/arm_psci.h
+++ b/include/kvm/arm_psci.h
@@ -13,8 +13,9 @@
#define KVM_ARM_PSCI_0_1 PSCI_VERSION(0, 1)
#define KVM_ARM_PSCI_0_2 PSCI_VERSION(0, 2)
#define KVM_ARM_PSCI_1_0 PSCI_VERSION(1, 0)
+#define KVM_ARM_PSCI_1_1 PSCI_VERSION(1, 1)
-#define KVM_ARM_PSCI_LATEST KVM_ARM_PSCI_1_0
+#define KVM_ARM_PSCI_LATEST KVM_ARM_PSCI_1_1
/*
* We need the KVM pointer independently from the vcpu as we can call
--
2.35.1.473.g83b2b277ed-goog
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^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH v2 2/3] KVM: arm64: Expose PSCI SYSTEM_RESET2 call to the guest
2022-02-21 15:35 [PATCH v2 0/3] Plumb PSCI SYSTEM_RESET2 call for guests Will Deacon
2022-02-21 15:35 ` [PATCH v2 1/3] KVM: arm64: Bump guest PSCI version to 1.1 Will Deacon
@ 2022-02-21 15:35 ` Will Deacon
2022-02-21 15:35 ` [PATCH v2 3/3] KVM: arm64: Indicate SYSTEM_RESET2 in kvm_run::system_event flags field Will Deacon
2022-02-21 16:11 ` [PATCH v2 0/3] Plumb PSCI SYSTEM_RESET2 call for guests Marc Zyngier
3 siblings, 0 replies; 5+ messages in thread
From: Will Deacon @ 2022-02-21 15:35 UTC (permalink / raw)
To: kvmarm
Cc: linux-arm-kernel, Will Deacon, Marc Zyngier, James Morse,
Alexandru Elisei, Suzuki K Poulose
PSCI v1.1 introduces the optional SYSTEM_RESET2 call, which allows the
caller to provide a vendor-specific "reset type" and "cookie" to request
a particular form of reset or shutdown.
Expose this call to the guest and handle it in the same way as PSCI
SYSTEM_RESET, along with some basic range checking on the type argument.
Cc: Marc Zyngier <maz@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/kvm/psci.c | 33 +++++++++++++++++++++++++++++----
include/uapi/linux/psci.h | 4 ++++
2 files changed, 33 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c
index 70d07477e712..30fcc5a99483 100644
--- a/arch/arm64/kvm/psci.c
+++ b/arch/arm64/kvm/psci.c
@@ -308,7 +308,7 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
static int kvm_psci_1_x_call(struct kvm_vcpu *vcpu, u32 minor)
{
u32 psci_fn = smccc_get_function(vcpu);
- u32 feature;
+ u32 arg;
unsigned long val;
int ret = 1;
@@ -320,12 +320,12 @@ static int kvm_psci_1_x_call(struct kvm_vcpu *vcpu, u32 minor)
val = minor == 0 ? KVM_ARM_PSCI_1_0 : KVM_ARM_PSCI_1_1;
break;
case PSCI_1_0_FN_PSCI_FEATURES:
- feature = smccc_get_arg1(vcpu);
- val = kvm_psci_check_allowed_function(vcpu, feature);
+ arg = smccc_get_arg1(vcpu);
+ val = kvm_psci_check_allowed_function(vcpu, arg);
if (val)
break;
- switch(feature) {
+ switch(arg) {
case PSCI_0_2_FN_PSCI_VERSION:
case PSCI_0_2_FN_CPU_SUSPEND:
case PSCI_0_2_FN64_CPU_SUSPEND:
@@ -341,11 +341,36 @@ static int kvm_psci_1_x_call(struct kvm_vcpu *vcpu, u32 minor)
case ARM_SMCCC_VERSION_FUNC_ID:
val = 0;
break;
+ case PSCI_1_1_FN_SYSTEM_RESET2:
+ case PSCI_1_1_FN64_SYSTEM_RESET2:
+ if (minor >= 1) {
+ val = 0;
+ break;
+ }
+ fallthrough;
default:
val = PSCI_RET_NOT_SUPPORTED;
break;
}
break;
+ case PSCI_1_1_FN_SYSTEM_RESET2:
+ kvm_psci_narrow_to_32bit(vcpu);
+ fallthrough;
+ case PSCI_1_1_FN64_SYSTEM_RESET2:
+ if (minor >= 1) {
+ arg = smccc_get_arg1(vcpu);
+
+ if (arg > PSCI_1_1_RESET_TYPE_SYSTEM_WARM_RESET &&
+ arg < PSCI_1_1_RESET_TYPE_VENDOR_START) {
+ val = PSCI_RET_INVALID_PARAMS;
+ } else {
+ kvm_psci_system_reset(vcpu);
+ val = PSCI_RET_INTERNAL_FAILURE;
+ ret = 0;
+ }
+ break;
+ };
+ fallthrough;
default:
return kvm_psci_0_2_call(vcpu);
}
diff --git a/include/uapi/linux/psci.h b/include/uapi/linux/psci.h
index 2fcad1dd0b0e..2bf93c0d6354 100644
--- a/include/uapi/linux/psci.h
+++ b/include/uapi/linux/psci.h
@@ -82,6 +82,10 @@
#define PSCI_0_2_TOS_UP_NO_MIGRATE 1
#define PSCI_0_2_TOS_MP 2
+/* PSCI v1.1 reset type encoding for SYSTEM_RESET2 */
+#define PSCI_1_1_RESET_TYPE_SYSTEM_WARM_RESET 0
+#define PSCI_1_1_RESET_TYPE_VENDOR_START 0x80000000U
+
/* PSCI version decoding (independent of PSCI version) */
#define PSCI_VERSION_MAJOR_SHIFT 16
#define PSCI_VERSION_MINOR_MASK \
--
2.35.1.473.g83b2b277ed-goog
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^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH v2 3/3] KVM: arm64: Indicate SYSTEM_RESET2 in kvm_run::system_event flags field
2022-02-21 15:35 [PATCH v2 0/3] Plumb PSCI SYSTEM_RESET2 call for guests Will Deacon
2022-02-21 15:35 ` [PATCH v2 1/3] KVM: arm64: Bump guest PSCI version to 1.1 Will Deacon
2022-02-21 15:35 ` [PATCH v2 2/3] KVM: arm64: Expose PSCI SYSTEM_RESET2 call to the guest Will Deacon
@ 2022-02-21 15:35 ` Will Deacon
2022-02-21 16:11 ` [PATCH v2 0/3] Plumb PSCI SYSTEM_RESET2 call for guests Marc Zyngier
3 siblings, 0 replies; 5+ messages in thread
From: Will Deacon @ 2022-02-21 15:35 UTC (permalink / raw)
To: kvmarm
Cc: linux-arm-kernel, Will Deacon, Marc Zyngier, James Morse,
Alexandru Elisei, Suzuki K Poulose
When handling reset and power-off PSCI calls from the guest, we
initialise X0 to PSCI_RET_INTERNAL_FAILURE in case the VMM tries to
re-run the vCPU after issuing the call.
Unfortunately, this also means that the VMM cannot see which PSCI call
was issued and therefore cannot distinguish between PSCI SYSTEM_RESET
and SYSTEM_RESET2 calls, which is necessary in order to determine the
validity of the "reset_type" in X1.
Allocate bit 0 of the previously unused 'flags' field of the
system_event structure so that we can indicate the PSCI call used to
initiate the reset.
Cc: Marc Zyngier <maz@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
Documentation/virt/kvm/api.rst | 5 +++++
arch/arm64/include/uapi/asm/kvm.h | 7 +++++++
arch/arm64/kvm/psci.c | 15 +++++++++++----
3 files changed, 23 insertions(+), 4 deletions(-)
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index a4267104db50..8305ac9747b6 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -5939,6 +5939,11 @@ Valid values for 'type' are:
to ignore the request, or to gather VM memory core dump and/or
reset/shutdown of the VM.
+Valid flags are:
+
+ - KVM_SYSTEM_EVENT_RESET_FLAG_PSCI_RESET2 (arm64 only) -- the guest issued
+ a SYSTEM_RESET2 call according to v1.1 of the PSCI specification.
+
::
/* KVM_EXIT_IOAPIC_EOI */
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index b3edde68bc3e..06bc08fdf8ea 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -413,6 +413,13 @@ struct kvm_arm_copy_mte_tags {
#define KVM_PSCI_RET_INVAL PSCI_RET_INVALID_PARAMS
#define KVM_PSCI_RET_DENIED PSCI_RET_DENIED
+/* arm64-specific kvm_run::system_event flags */
+/*
+ * Reset caused by a PSCI v1.1 SYSTEM_RESET2 call.
+ * Valid only when the system event has a type of KVM_SYSTEM_EVENT_RESET.
+ */
+#define KVM_SYSTEM_EVENT_RESET_FLAG_PSCI_RESET2 (1ULL << 0)
+
#endif
#endif /* __ARM_KVM_H__ */
diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c
index 30fcc5a99483..ecb4b74cb12a 100644
--- a/arch/arm64/kvm/psci.c
+++ b/arch/arm64/kvm/psci.c
@@ -162,7 +162,7 @@ static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu)
return PSCI_0_2_AFFINITY_LEVEL_OFF;
}
-static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type)
+static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type, u64 flags)
{
unsigned long i;
struct kvm_vcpu *tmp;
@@ -182,17 +182,24 @@ static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type)
memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event));
vcpu->run->system_event.type = type;
+ vcpu->run->system_event.flags = flags;
vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
}
static void kvm_psci_system_off(struct kvm_vcpu *vcpu)
{
- kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_SHUTDOWN);
+ kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_SHUTDOWN, 0);
}
static void kvm_psci_system_reset(struct kvm_vcpu *vcpu)
{
- kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_RESET);
+ kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_RESET, 0);
+}
+
+static void kvm_psci_system_reset2(struct kvm_vcpu *vcpu)
+{
+ kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_RESET,
+ KVM_SYSTEM_EVENT_RESET_FLAG_PSCI_RESET2);
}
static void kvm_psci_narrow_to_32bit(struct kvm_vcpu *vcpu)
@@ -364,7 +371,7 @@ static int kvm_psci_1_x_call(struct kvm_vcpu *vcpu, u32 minor)
arg < PSCI_1_1_RESET_TYPE_VENDOR_START) {
val = PSCI_RET_INVALID_PARAMS;
} else {
- kvm_psci_system_reset(vcpu);
+ kvm_psci_system_reset2(vcpu);
val = PSCI_RET_INTERNAL_FAILURE;
ret = 0;
}
--
2.35.1.473.g83b2b277ed-goog
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^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH v2 0/3] Plumb PSCI SYSTEM_RESET2 call for guests
2022-02-21 15:35 [PATCH v2 0/3] Plumb PSCI SYSTEM_RESET2 call for guests Will Deacon
` (2 preceding siblings ...)
2022-02-21 15:35 ` [PATCH v2 3/3] KVM: arm64: Indicate SYSTEM_RESET2 in kvm_run::system_event flags field Will Deacon
@ 2022-02-21 16:11 ` Marc Zyngier
3 siblings, 0 replies; 5+ messages in thread
From: Marc Zyngier @ 2022-02-21 16:11 UTC (permalink / raw)
To: kvmarm, Will Deacon; +Cc: linux-arm-kernel
On Mon, 21 Feb 2022 15:35:21 +0000, Will Deacon wrote:
> Here's version two of the patches I posted at the end of last week:
>
> https://lore.kernel.org/r/20220217184001.11753-1-will@kernel.org
>
> The only change is to the comments and ABI documentation, so that we
> refer to the PSCI spec instead of describing the arguments to RESET2.
>
> [...]
Applied to next, thanks!
[1/3] KVM: arm64: Bump guest PSCI version to 1.1
commit: 512865d83fd9685a4d5aab26f898737b57d3187e
[2/3] KVM: arm64: Expose PSCI SYSTEM_RESET2 call to the guest
commit: d43583b890e7cb0078d13d056753a56602b92406
[3/3] KVM: arm64: Indicate SYSTEM_RESET2 in kvm_run::system_event flags field
commit: 34739fd95fab3a5efb0422e4f012b685e33598dc
Cheers,
M.
--
Without deviation from the norm, progress is not possible.
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^ permalink raw reply [flat|nested] 5+ messages in thread