From: Marc Zyngier <maz@kernel.org>
To: Jianyong Wu <jianyong.wu@arm.com>
Cc: justin.he@arm.com, kvm@vger.kernel.org, netdev@vger.kernel.org,
richardcochran@gmail.com, linux-kernel@vger.kernel.org,
sean.j.christopherson@intel.com, steven.price@arm.com,
Andre.Przywara@arm.com, john.stultz@linaro.org,
yangbo.lu@nxp.com, pbonzini@redhat.com, tglx@linutronix.de,
nd@arm.com, will@kernel.org, kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v15 6/9] arm64/kvm: Add hypercall service for kvm ptp.
Date: Mon, 23 Nov 2020 11:59:09 +0000 [thread overview]
Message-ID: <276428d3d291f703e2f0c2c323194e98@kernel.org> (raw)
In-Reply-To: <d409aa1cb7cfcbf4351e6c5fc34d9c7e@kernel.org>
On 2020-11-23 10:44, Marc Zyngier wrote:
> On 2020-11-11 06:22, Jianyong Wu wrote:
>> ptp_kvm will get this service through SMCC call.
>> The service offers wall time and cycle count of host to guest.
>> The caller must specify whether they want the host cycle count
>> or the difference between host cycle count and cntvoff.
>>
>> Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>
>> ---
>> arch/arm64/kvm/hypercalls.c | 61
>> +++++++++++++++++++++++++++++++++++++
>> include/linux/arm-smccc.h | 17 +++++++++++
>> 2 files changed, 78 insertions(+)
>>
>> diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c
>> index b9d8607083eb..f7d189563f3d 100644
>> --- a/arch/arm64/kvm/hypercalls.c
>> +++ b/arch/arm64/kvm/hypercalls.c
>> @@ -9,6 +9,51 @@
>> #include <kvm/arm_hypercalls.h>
>> #include <kvm/arm_psci.h>
>>
>> +static void kvm_ptp_get_time(struct kvm_vcpu *vcpu, u64 *val)
>> +{
>> + struct system_time_snapshot systime_snapshot;
>> + u64 cycles = ~0UL;
>> + u32 feature;
>> +
>> + /*
>> + * system time and counter value must captured in the same
>> + * time to keep consistency and precision.
>> + */
>> + ktime_get_snapshot(&systime_snapshot);
>> +
>> + // binding ptp_kvm clocksource to arm_arch_counter
>> + if (systime_snapshot.cs_id != CSID_ARM_ARCH_COUNTER)
>> + return;
>> +
>> + val[0] = upper_32_bits(systime_snapshot.real);
>> + val[1] = lower_32_bits(systime_snapshot.real);
>
> What is the endianness of these values? I can't see it defined
> anywhere, and this is likely not to work if guest and hypervisor
> don't align.
Scratch that. This is all passed via registers, so the endianness
of the data is irrelevant. Please discard any comment about endianness
I made in this review.
The documentation aspect still requires to be beefed up.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: Jianyong Wu <jianyong.wu@arm.com>
Cc: justin.he@arm.com, kvm@vger.kernel.org, netdev@vger.kernel.org,
richardcochran@gmail.com, yangbo.lu@nxp.com,
linux-kernel@vger.kernel.org, sean.j.christopherson@intel.com,
steven.price@arm.com, john.stultz@linaro.org,
Andre.Przywara@arm.com, pbonzini@redhat.com, tglx@linutronix.de,
nd@arm.com, will@kernel.org, kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v15 6/9] arm64/kvm: Add hypercall service for kvm ptp.
Date: Mon, 23 Nov 2020 11:59:09 +0000 [thread overview]
Message-ID: <276428d3d291f703e2f0c2c323194e98@kernel.org> (raw)
In-Reply-To: <d409aa1cb7cfcbf4351e6c5fc34d9c7e@kernel.org>
On 2020-11-23 10:44, Marc Zyngier wrote:
> On 2020-11-11 06:22, Jianyong Wu wrote:
>> ptp_kvm will get this service through SMCC call.
>> The service offers wall time and cycle count of host to guest.
>> The caller must specify whether they want the host cycle count
>> or the difference between host cycle count and cntvoff.
>>
>> Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>
>> ---
>> arch/arm64/kvm/hypercalls.c | 61
>> +++++++++++++++++++++++++++++++++++++
>> include/linux/arm-smccc.h | 17 +++++++++++
>> 2 files changed, 78 insertions(+)
>>
>> diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c
>> index b9d8607083eb..f7d189563f3d 100644
>> --- a/arch/arm64/kvm/hypercalls.c
>> +++ b/arch/arm64/kvm/hypercalls.c
>> @@ -9,6 +9,51 @@
>> #include <kvm/arm_hypercalls.h>
>> #include <kvm/arm_psci.h>
>>
>> +static void kvm_ptp_get_time(struct kvm_vcpu *vcpu, u64 *val)
>> +{
>> + struct system_time_snapshot systime_snapshot;
>> + u64 cycles = ~0UL;
>> + u32 feature;
>> +
>> + /*
>> + * system time and counter value must captured in the same
>> + * time to keep consistency and precision.
>> + */
>> + ktime_get_snapshot(&systime_snapshot);
>> +
>> + // binding ptp_kvm clocksource to arm_arch_counter
>> + if (systime_snapshot.cs_id != CSID_ARM_ARCH_COUNTER)
>> + return;
>> +
>> + val[0] = upper_32_bits(systime_snapshot.real);
>> + val[1] = lower_32_bits(systime_snapshot.real);
>
> What is the endianness of these values? I can't see it defined
> anywhere, and this is likely not to work if guest and hypervisor
> don't align.
Scratch that. This is all passed via registers, so the endianness
of the data is irrelevant. Please discard any comment about endianness
I made in this review.
The documentation aspect still requires to be beefed up.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: Jianyong Wu <jianyong.wu@arm.com>
Cc: justin.he@arm.com, kvm@vger.kernel.org, netdev@vger.kernel.org,
richardcochran@gmail.com, yangbo.lu@nxp.com,
linux-kernel@vger.kernel.org, sean.j.christopherson@intel.com,
steven.price@arm.com, john.stultz@linaro.org,
Andre.Przywara@arm.com, pbonzini@redhat.com, tglx@linutronix.de,
nd@arm.com, will@kernel.org, kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v15 6/9] arm64/kvm: Add hypercall service for kvm ptp.
Date: Mon, 23 Nov 2020 11:59:09 +0000 [thread overview]
Message-ID: <276428d3d291f703e2f0c2c323194e98@kernel.org> (raw)
In-Reply-To: <d409aa1cb7cfcbf4351e6c5fc34d9c7e@kernel.org>
On 2020-11-23 10:44, Marc Zyngier wrote:
> On 2020-11-11 06:22, Jianyong Wu wrote:
>> ptp_kvm will get this service through SMCC call.
>> The service offers wall time and cycle count of host to guest.
>> The caller must specify whether they want the host cycle count
>> or the difference between host cycle count and cntvoff.
>>
>> Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>
>> ---
>> arch/arm64/kvm/hypercalls.c | 61
>> +++++++++++++++++++++++++++++++++++++
>> include/linux/arm-smccc.h | 17 +++++++++++
>> 2 files changed, 78 insertions(+)
>>
>> diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c
>> index b9d8607083eb..f7d189563f3d 100644
>> --- a/arch/arm64/kvm/hypercalls.c
>> +++ b/arch/arm64/kvm/hypercalls.c
>> @@ -9,6 +9,51 @@
>> #include <kvm/arm_hypercalls.h>
>> #include <kvm/arm_psci.h>
>>
>> +static void kvm_ptp_get_time(struct kvm_vcpu *vcpu, u64 *val)
>> +{
>> + struct system_time_snapshot systime_snapshot;
>> + u64 cycles = ~0UL;
>> + u32 feature;
>> +
>> + /*
>> + * system time and counter value must captured in the same
>> + * time to keep consistency and precision.
>> + */
>> + ktime_get_snapshot(&systime_snapshot);
>> +
>> + // binding ptp_kvm clocksource to arm_arch_counter
>> + if (systime_snapshot.cs_id != CSID_ARM_ARCH_COUNTER)
>> + return;
>> +
>> + val[0] = upper_32_bits(systime_snapshot.real);
>> + val[1] = lower_32_bits(systime_snapshot.real);
>
> What is the endianness of these values? I can't see it defined
> anywhere, and this is likely not to work if guest and hypervisor
> don't align.
Scratch that. This is all passed via registers, so the endianness
of the data is irrelevant. Please discard any comment about endianness
I made in this review.
The documentation aspect still requires to be beefed up.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-11-23 11:59 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-11 6:22 [PATCH v15 0/9] Enable ptp_kvm for arm/arm64 Jianyong Wu
2020-11-11 6:22 ` Jianyong Wu
2020-11-11 6:22 ` Jianyong Wu
2020-11-11 6:22 ` [PATCH v15 1/9] arm64: Probe for the presence of KVM hypervisor Jianyong Wu
2020-11-11 6:22 ` Jianyong Wu
2020-11-11 6:22 ` Jianyong Wu
2020-11-11 10:38 ` kernel test robot
2020-11-11 12:23 ` kernel test robot
2020-11-11 16:54 ` kernel test robot
2020-11-11 6:22 ` [PATCH v15 2/9] arm/arm64: KVM: Advertise KVM UID to guests via SMCCC Jianyong Wu
2020-11-11 6:22 ` Jianyong Wu
2020-11-11 6:22 ` Jianyong Wu
2020-11-11 6:22 ` [PATCH v15 3/9] ptp: Reorganize ptp_kvm module to make it arch-independent Jianyong Wu
2020-11-11 6:22 ` Jianyong Wu
2020-11-11 6:22 ` Jianyong Wu
2020-11-11 13:10 ` kernel test robot
2020-11-11 13:10 ` kernel test robot
2020-11-11 14:36 ` kernel test robot
2020-11-11 14:36 ` kernel test robot
2020-11-11 6:22 ` [PATCH v15 4/9] time: Add mechanism to recognize clocksource in time_get_snapshot Jianyong Wu
2020-11-11 6:22 ` Jianyong Wu
2020-11-11 6:22 ` Jianyong Wu
2020-11-11 6:22 ` [PATCH v15 5/9] clocksource: Add clocksource id for arm arch counter Jianyong Wu
2020-11-11 6:22 ` Jianyong Wu
2020-11-11 6:22 ` Jianyong Wu
2020-11-11 6:22 ` [PATCH v15 6/9] arm64/kvm: Add hypercall service for kvm ptp Jianyong Wu
2020-11-11 6:22 ` Jianyong Wu
2020-11-11 6:22 ` Jianyong Wu
2020-11-23 10:44 ` Marc Zyngier
2020-11-23 10:44 ` Marc Zyngier
2020-11-23 10:44 ` Marc Zyngier
2020-11-23 11:59 ` Marc Zyngier [this message]
2020-11-23 11:59 ` Marc Zyngier
2020-11-23 11:59 ` Marc Zyngier
2020-11-24 5:11 ` Jianyong Wu
2020-11-24 5:11 ` Jianyong Wu
2020-11-24 5:11 ` Jianyong Wu
2020-11-24 5:20 ` Jianyong Wu
2020-11-24 5:20 ` Jianyong Wu
2020-11-24 5:20 ` Jianyong Wu
2020-11-24 9:07 ` Marc Zyngier
2020-11-24 9:07 ` Marc Zyngier
2020-11-24 9:07 ` Marc Zyngier
2020-11-24 10:14 ` Jianyong Wu
2020-11-24 10:14 ` Jianyong Wu
2020-11-24 10:14 ` Jianyong Wu
2020-11-11 6:22 ` [PATCH v15 7/9] ptp: arm/arm64: Enable ptp_kvm for arm/arm64 Jianyong Wu
2020-11-11 6:22 ` Jianyong Wu
2020-11-11 6:22 ` Jianyong Wu
2020-11-11 8:52 ` kernel test robot
2020-11-11 8:52 ` kernel test robot
2020-11-11 13:44 ` kernel test robot
2020-11-11 13:44 ` kernel test robot
2020-12-04 9:46 ` Jianyong Wu
2020-11-23 10:49 ` Marc Zyngier
2020-11-23 10:49 ` Marc Zyngier
2020-11-23 10:49 ` Marc Zyngier
2020-11-24 5:37 ` Jianyong Wu
2020-11-24 5:37 ` Jianyong Wu
2020-11-24 5:37 ` Jianyong Wu
2020-11-24 9:04 ` Marc Zyngier
2020-11-24 9:04 ` Marc Zyngier
2020-11-24 9:04 ` Marc Zyngier
2020-11-24 10:18 ` Jianyong Wu
2020-11-24 10:18 ` Jianyong Wu
2020-11-24 10:18 ` Jianyong Wu
2020-11-11 6:22 ` [PATCH v15 8/9] doc: add ptp_kvm introduction for arm64 support Jianyong Wu
2020-11-11 6:22 ` Jianyong Wu
2020-11-11 6:22 ` Jianyong Wu
2020-11-23 10:58 ` Marc Zyngier
2020-11-23 10:58 ` Marc Zyngier
2020-11-23 10:58 ` Marc Zyngier
2020-11-24 5:21 ` Jianyong Wu
2020-11-24 5:21 ` Jianyong Wu
2020-11-24 5:21 ` Jianyong Wu
2020-11-11 6:22 ` [PATCH v15 9/9] arm64: Add kvm capability check extension for ptp_kvm Jianyong Wu
2020-11-11 6:22 ` Jianyong Wu
2020-11-11 6:22 ` Jianyong Wu
2020-11-23 9:26 ` [PATCH v15 0/9] Enable ptp_kvm for arm/arm64 Jianyong Wu
2020-11-23 9:26 ` Jianyong Wu
2020-11-23 9:26 ` Jianyong Wu
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