* Re: [PATCH 4/9] x86/mm/tlb: Flush remote and local TLBs concurrently
From: Nadav Amit @ 2019-06-26 3:32 UTC (permalink / raw)
To: Dave Hansen
Cc: Peter Zijlstra, Andy Lutomirski, LKML, Ingo Molnar,
Borislav Petkov, the arch/x86 maintainers, Thomas Gleixner,
Dave Hansen, K. Y. Srinivasan, Haiyang Zhang, Stephen Hemminger,
Sasha Levin, Juergen Gross, Paolo Bonzini, Boris Ostrovsky,
linux-hyperv@vger.kernel.org,
virtualization@lists.linux-foundation.org, kvm@vger.kernel.org,
xen-devel@lists.xenproject.org
In-Reply-To: <88a76cb8-2484-818a-2be6-d06a4ffef107@intel.com>
> On Jun 25, 2019, at 8:00 PM, Dave Hansen <dave.hansen@intel.com> wrote:
>
> On 6/25/19 7:35 PM, Nadav Amit wrote:
>>>> const struct flush_tlb_info *f = info;
>>>> + enum tlb_flush_reason reason;
>>>> +
>>>> + reason = (f->mm == NULL) ? TLB_LOCAL_SHOOTDOWN : TLB_LOCAL_MM_SHOOTDOWN;
>>>
>>> Should we just add the "reason" to flush_tlb_info? It's OK-ish to imply
>>> it like this, but seems like it would be nicer and easier to track down
>>> the origins of these things if we did this at the caller.
>>
>> I prefer not to. I want later to inline flush_tlb_info into the same
>> cacheline that holds call_function_data. Increasing the size of
>> flush_tlb_info for no good reason will not help…
>
> Well, flush_tlb_info is at 6/8ths of a cacheline at the moment.
> call_function_data is 3/8ths. To me, that means we have some slack in
> the size.
I do not understand your math.. :(
6 + 3 > 8 so putting both flush_tlb_info and call_function_data does not
leave us any slack (we can save one qword, so we can actually put them
at the same cacheline).
You can see my current implementation here:
https://lore.kernel.org/lkml/20190531063645.4697-4-namit@vmware.com/T/#m0ab5fe0799ba9ff0d41197f1095679fe26aebd57
https://lore.kernel.org/lkml/20190531063645.4697-4-namit@vmware.com/T/#m7b35a93dffd23fbb7ca813c795a0777d4cdcb51b
^ permalink raw reply
* Re: [PATCH 4/9] x86/mm/tlb: Flush remote and local TLBs concurrently
From: Andy Lutomirski @ 2019-06-26 3:36 UTC (permalink / raw)
To: Nadav Amit
Cc: Peter Zijlstra, Andy Lutomirski, LKML, Ingo Molnar,
Borislav Petkov, X86 ML, Thomas Gleixner, Dave Hansen,
K. Y. Srinivasan, Haiyang Zhang, Stephen Hemminger, Sasha Levin,
Juergen Gross, Paolo Bonzini, Boris Ostrovsky, linux-hyperv,
Linux Virtualization, kvm list, xen-devel
In-Reply-To: <20190613064813.8102-5-namit@vmware.com>
On Wed, Jun 12, 2019 at 11:49 PM Nadav Amit <namit@vmware.com> wrote:
>
> To improve TLB shootdown performance, flush the remote and local TLBs
> concurrently. Introduce flush_tlb_multi() that does so. The current
> flush_tlb_others() interface is kept, since paravirtual interfaces need
> to be adapted first before it can be removed. This is left for future
> work. In such PV environments, TLB flushes are not performed, at this
> time, concurrently.
Would it be straightforward to have a default PV flush_tlb_multi()
that uses flush_tlb_others() under the hood?
^ permalink raw reply
* Re: [PATCH 4/9] x86/mm/tlb: Flush remote and local TLBs concurrently
From: Nadav Amit @ 2019-06-26 3:48 UTC (permalink / raw)
To: Andy Lutomirski
Cc: Peter Zijlstra, LKML, Ingo Molnar, Borislav Petkov, X86 ML,
Thomas Gleixner, Dave Hansen, K. Y. Srinivasan, Haiyang Zhang,
Stephen Hemminger, Sasha Levin, Juergen Gross, Paolo Bonzini,
Boris Ostrovsky, linux-hyperv@vger.kernel.org,
Linux Virtualization, kvm list, xen-devel
In-Reply-To: <CALCETrXyJ8y7PSqf+RmGKjM4VSLXmNEGi6K=Jzw4jmckRQECTg@mail.gmail.com>
> On Jun 25, 2019, at 8:36 PM, Andy Lutomirski <luto@kernel.org> wrote:
>
> On Wed, Jun 12, 2019 at 11:49 PM Nadav Amit <namit@vmware.com> wrote:
>> To improve TLB shootdown performance, flush the remote and local TLBs
>> concurrently. Introduce flush_tlb_multi() that does so. The current
>> flush_tlb_others() interface is kept, since paravirtual interfaces need
>> to be adapted first before it can be removed. This is left for future
>> work. In such PV environments, TLB flushes are not performed, at this
>> time, concurrently.
>
> Would it be straightforward to have a default PV flush_tlb_multi()
> that uses flush_tlb_others() under the hood?
I prefer not to have a default PV implementation that should anyhow go away.
I can create unoptimized untested versions for Xen and Hyper-V, if you want.
^ permalink raw reply
* Re: [PATCH 4/9] x86/mm/tlb: Flush remote and local TLBs concurrently
From: Andy Lutomirski @ 2019-06-26 3:51 UTC (permalink / raw)
To: Nadav Amit
Cc: Andy Lutomirski, Peter Zijlstra, LKML, Ingo Molnar,
Borislav Petkov, X86 ML, Thomas Gleixner, Dave Hansen,
K. Y. Srinivasan, Haiyang Zhang, Stephen Hemminger, Sasha Levin,
Juergen Gross, Paolo Bonzini, Boris Ostrovsky,
linux-hyperv@vger.kernel.org, Linux Virtualization, kvm list,
xen-devel
In-Reply-To: <28C3D489-54E4-4670-B726-21B09FA469EE@vmware.com>
On Tue, Jun 25, 2019 at 8:48 PM Nadav Amit <namit@vmware.com> wrote:
>
> > On Jun 25, 2019, at 8:36 PM, Andy Lutomirski <luto@kernel.org> wrote:
> >
> > On Wed, Jun 12, 2019 at 11:49 PM Nadav Amit <namit@vmware.com> wrote:
> >> To improve TLB shootdown performance, flush the remote and local TLBs
> >> concurrently. Introduce flush_tlb_multi() that does so. The current
> >> flush_tlb_others() interface is kept, since paravirtual interfaces need
> >> to be adapted first before it can be removed. This is left for future
> >> work. In such PV environments, TLB flushes are not performed, at this
> >> time, concurrently.
> >
> > Would it be straightforward to have a default PV flush_tlb_multi()
> > that uses flush_tlb_others() under the hood?
>
> I prefer not to have a default PV implementation that should anyhow go away.
>
> I can create unoptimized untested versions for Xen and Hyper-V, if you want.
>
I think I prefer that approach. We should be able to get the
maintainers to test it. I don't love having legacy paths in there,
ahem, UV.
^ permalink raw reply
* [PATCH RESEND] locking/spinlocks, paravirt, hyperv: Correct the hv_nopvspin case
From: Zhenzhong Duan @ 2019-06-26 8:56 UTC (permalink / raw)
To: linux-kernel
Cc: Zhenzhong Duan, Waiman Long, Peter Zijlstra (Intel),
K. Y. Srinivasan, Haiyang Zhang, Stephen Hemminger, Sasha Levin,
Thomas Gleixner, Ingo Molnar, Borislav Petkov, linux-hyperv
With the boot parameter "hv_nopvspin" specified a Hyperv guest should
not make use of paravirt spinlocks, but behave as if running on bare
metal. This is not true, however, as the qspinlock code will fall back
to a test-and-set scheme when it is detecting a hypervisor.
In order to avoid this disable the virt_spin_lock_key.
Same change for XEN is already in Commit e6fd28eb3522
("locking/spinlocks, paravirt, xen: Correct the xen_nopvspin case")
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: linux-hyperv@vger.kernel.org
---
arch/x86/hyperv/hv_spinlock.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/x86/hyperv/hv_spinlock.c b/arch/x86/hyperv/hv_spinlock.c
index 07f21a0..d90b4b0 100644
--- a/arch/x86/hyperv/hv_spinlock.c
+++ b/arch/x86/hyperv/hv_spinlock.c
@@ -64,6 +64,9 @@ __visible bool hv_vcpu_is_preempted(int vcpu)
void __init hv_init_spinlocks(void)
{
+ if (unlikely(!hv_pvspin))
+ static_branch_disable(&virt_spin_lock_key);
+
if (!hv_pvspin || !apic ||
!(ms_hyperv.hints & HV_X64_CLUSTER_IPI_RECOMMENDED) ||
!(ms_hyperv.features & HV_X64_MSR_GUEST_IDLE_AVAILABLE)) {
--
1.8.3.1
^ permalink raw reply related
* Re: [PATCH v3 2/5] x86: hv: hv_init.c: Add functions to allocate/deallocate page for Hyper-V
From: Thomas Gleixner @ 2019-06-27 21:38 UTC (permalink / raw)
To: Maya Nakamura
Cc: mikelley, kys, haiyangz, sthemmin, sashal, x86, linux-hyperv,
linux-kernel
In-Reply-To: <d19c28cda88bf1706baff883380dfd321da30a68.1560837096.git.m.maya.nakamura@gmail.com>
Maya,
On Tue, 18 Jun 2019, Maya Nakamura wrote:
> diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
> index 0e033ef11a9f..e8960a83add7 100644
> --- a/arch/x86/hyperv/hv_init.c
> +++ b/arch/x86/hyperv/hv_init.c
> @@ -37,6 +37,20 @@ EXPORT_SYMBOL_GPL(hyperv_pcpu_input_arg);
> u32 hv_max_vp_index;
> EXPORT_SYMBOL_GPL(hv_max_vp_index);
>
> +void *hv_alloc_hyperv_page(void)
> +{
> + BUILD_BUG_ON(PAGE_SIZE != HV_HYP_PAGE_SIZE);
> +
> + return (void *)__get_free_page(GFP_KERNEL);
> +}
> +EXPORT_SYMBOL_GPL(hv_alloc_hyperv_page);
> +
> +void hv_free_hyperv_page(unsigned long addr)
> +{
> + free_page(addr);
> +}
> +EXPORT_SYMBOL_GPL(hv_free_hyperv_page);
These functions need to be declared in a header file.
Thanks,
tglx
^ permalink raw reply
* Re: [PATCH v2 6/7] locking/spinlocks, paravirt, hyperv: Correct the hv_nopvspin case
From: Sasha Levin @ 2019-06-27 22:28 UTC (permalink / raw)
To: Zhenzhong Duan
Cc: linux-kernel, tglx, mingo, bp, hpa, boris.ostrovsky, jgross,
sstabellini, peterz, srinivas.eeda, Waiman Long, K. Y. Srinivasan,
Haiyang Zhang, Stephen Hemminger, Ingo Molnar, linux-hyperv
In-Reply-To: <1561377779-28036-7-git-send-email-zhenzhong.duan@oracle.com>
On Mon, Jun 24, 2019 at 08:02:58PM +0800, Zhenzhong Duan wrote:
>With the boot parameter "hv_nopvspin" specified a Hyperv guest should
>not make use of paravirt spinlocks, but behave as if running on bare
>metal. This is not true, however, as the qspinlock code will fall back
>to a test-and-set scheme when it is detecting a hypervisor.
>
>In order to avoid this disable the virt_spin_lock_key.
>
>Same change for XEN is already in Commit e6fd28eb3522
>("locking/spinlocks, paravirt, xen: Correct the xen_nopvspin case")
>
>Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
>Cc: Waiman Long <longman@redhat.com>
>Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
>Cc: "K. Y. Srinivasan" <kys@microsoft.com>
>Cc: Haiyang Zhang <haiyangz@microsoft.com>
>Cc: Stephen Hemminger <sthemmin@microsoft.com>
>Cc: Sasha Levin <sashal@kernel.org>
>Cc: Thomas Gleixner <tglx@linutronix.de>
>Cc: Ingo Molnar <mingo@redhat.com>
>Cc: Borislav Petkov <bp@alien8.de>
>Cc: linux-hyperv@vger.kernel.org
>---
> arch/x86/hyperv/hv_spinlock.c | 3 +++
> 1 file changed, 3 insertions(+)
>
>diff --git a/arch/x86/hyperv/hv_spinlock.c b/arch/x86/hyperv/hv_spinlock.c
>index 07f21a0..d90b4b0 100644
>--- a/arch/x86/hyperv/hv_spinlock.c
>+++ b/arch/x86/hyperv/hv_spinlock.c
>@@ -64,6 +64,9 @@ __visible bool hv_vcpu_is_preempted(int vcpu)
>
> void __init hv_init_spinlocks(void)
> {
>+ if (unlikely(!hv_pvspin))
>+ static_branch_disable(&virt_spin_lock_key);
This should be combined in the conditional under it, which already
attempts to disable PV spinlocks, note how hv_pvspin is checked there.
hc_pvspin isn't the only reason we would disable PV spinlocks on hyperv.
Also, there's no need for the unlikely() here, it's only getting called
once...
--
Thanks,
Sasha
^ permalink raw reply
* Re: [PATCHv2] x86/hyperv: Hold cpus_read_lock() on assigning reenlightenment vector
From: Thomas Gleixner @ 2019-06-27 22:39 UTC (permalink / raw)
To: Dmitry Safonov
Cc: linux-kernel, Dmitry Safonov, Prasanna Panchamukhi,
Andy Lutomirski, Borislav Petkov, Cathy Avery, Haiyang Zhang,
H. Peter Anvin, Ingo Molnar, K. Y. Srinivasan,
Michael Kelley (EOSG), Mohammed Gamal, Paolo Bonzini,
Peter Zijlstra, Radim Krčmář, Roman Kagan,
Sasha Levin, Stephen Hemminger, Vitaly Kuznetsov, devel, kvm,
linux-hyperv, x86
In-Reply-To: <20190617163955.25659-1-dima@arista.com>
On Mon, 17 Jun 2019, Dmitry Safonov wrote:
> @@ -196,7 +196,16 @@ void set_hv_tscchange_cb(void (*cb)(void))
> /* Make sure callback is registered before we write to MSRs */
> wmb();
>
> + /*
> + * As reenlightenment vector is global, there is no difference which
> + * CPU will register MSR, though it should be an online CPU.
> + * hv_cpu_die() callback guarantees that on CPU teardown
> + * another CPU will re-register MSR back.
> + */
> + cpus_read_lock();
> + re_ctrl.target_vp = hv_vp_index[raw_smp_processor_id()];
> wrmsrl(HV_X64_MSR_REENLIGHTENMENT_CONTROL, *((u64 *)&re_ctrl));
> + cpus_read_unlock();
Should work
> wrmsrl(HV_X64_MSR_TSC_EMULATION_CONTROL, *((u64 *)&emu_ctrl));
> }
> EXPORT_SYMBOL_GPL(set_hv_tscchange_cb);
> @@ -239,6 +248,7 @@ static int hv_cpu_die(unsigned int cpu)
>
> rdmsrl(HV_X64_MSR_REENLIGHTENMENT_CONTROL, *((u64 *)&re_ctrl));
> if (re_ctrl.target_vp == hv_vp_index[cpu]) {
> + lockdep_assert_cpus_held();
So you're not trusting the hotplug core code to hold the lock when it
brings a CPU down and invokes that callback? Come on
> /* Reassign to some other online CPU */
> new_cpu = cpumask_any_but(cpu_online_mask, cpu);
Thanks,
tglx
^ permalink raw reply
* Re: [PATCH v2 6/7] locking/spinlocks, paravirt, hyperv: Correct the hv_nopvspin case
From: Zhenzhong Duan @ 2019-06-28 0:53 UTC (permalink / raw)
To: Sasha Levin
Cc: linux-kernel, tglx, mingo, bp, hpa, boris.ostrovsky, jgross,
sstabellini, peterz, srinivas.eeda, Waiman Long, K. Y. Srinivasan,
Haiyang Zhang, Stephen Hemminger, Ingo Molnar, linux-hyperv
In-Reply-To: <20190627222851.GC11506@sasha-vm>
On 2019/6/28 6:28, Sasha Levin wrote:
> On Mon, Jun 24, 2019 at 08:02:58PM +0800, Zhenzhong Duan wrote:
>> With the boot parameter "hv_nopvspin" specified a Hyperv guest should
>> not make use of paravirt spinlocks, but behave as if running on bare
>> metal. This is not true, however, as the qspinlock code will fall back
>> to a test-and-set scheme when it is detecting a hypervisor.
>>
>> In order to avoid this disable the virt_spin_lock_key.
>>
>> Same change for XEN is already in Commit e6fd28eb3522
>> ("locking/spinlocks, paravirt, xen: Correct the xen_nopvspin case")
>>
>> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
>> Cc: Waiman Long <longman@redhat.com>
>> Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
>> Cc: "K. Y. Srinivasan" <kys@microsoft.com>
>> Cc: Haiyang Zhang <haiyangz@microsoft.com>
>> Cc: Stephen Hemminger <sthemmin@microsoft.com>
>> Cc: Sasha Levin <sashal@kernel.org>
>> Cc: Thomas Gleixner <tglx@linutronix.de>
>> Cc: Ingo Molnar <mingo@redhat.com>
>> Cc: Borislav Petkov <bp@alien8.de>
>> Cc: linux-hyperv@vger.kernel.org
>> ---
>> arch/x86/hyperv/hv_spinlock.c | 3 +++
>> 1 file changed, 3 insertions(+)
>>
>> diff --git a/arch/x86/hyperv/hv_spinlock.c
>> b/arch/x86/hyperv/hv_spinlock.c
>> index 07f21a0..d90b4b0 100644
>> --- a/arch/x86/hyperv/hv_spinlock.c
>> +++ b/arch/x86/hyperv/hv_spinlock.c
>> @@ -64,6 +64,9 @@ __visible bool hv_vcpu_is_preempted(int vcpu)
>>
>> void __init hv_init_spinlocks(void)
>> {
>> + if (unlikely(!hv_pvspin))
>> + static_branch_disable(&virt_spin_lock_key);
>
> This should be combined in the conditional under it, which already
> attempts to disable PV spinlocks, note how hv_pvspin is checked there.
> hc_pvspin isn't the only reason we would disable PV spinlocks on hyperv.
In virt_spin_lock() there is a comment as below. The test-and-set spinlock
is an optimization to hypervisor platform when PV spinlock is unsupported.
/*
* On hypervisors without PARAVIRT_SPINLOCKS support we fall
* back to a Test-and-Set spinlock, because fair locks have
* horrible lock 'holder' preemption issues.
*/
So my understanding is:
If hv_pvspin=0 by command line, we want to behave as if running on bare
metal(the fair locks path).
Though there is performance regression, but it's not that important when
we use hv_pvspin=0.
If PV spinlock is disabled by other reasons, we prefer the optimization
path.
>
> Also, there's no need for the unlikely() here, it's only getting called
> once...
Ok, I'll removed it.
Thanks
Zhenzhong
^ permalink raw reply
* [PATCH v1] Tools: hv: move to tools buildsystem
From: Andy Shevchenko @ 2019-06-28 17:05 UTC (permalink / raw)
To: K. Y. Srinivasan, Haiyang Zhang, Stephen Hemminger, linux-hyperv,
Sasha Levin
Cc: Andy Shevchenko
There is a nice buildsystem dedicated for userspace tools in Linux kernel tree.
Switch gpio target to be built by it.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
tools/hv/Build | 3 +++
tools/hv/Makefile | 51 +++++++++++++++++++++++++++++++++++++----------
2 files changed, 44 insertions(+), 10 deletions(-)
create mode 100644 tools/hv/Build
diff --git a/tools/hv/Build b/tools/hv/Build
new file mode 100644
index 000000000000..6cf51fa4b306
--- /dev/null
+++ b/tools/hv/Build
@@ -0,0 +1,3 @@
+hv_kvp_daemon-y += hv_kvp_daemon.o
+hv_vss_daemon-y += hv_vss_daemon.o
+hv_fcopy_daemon-y += hv_fcopy_daemon.o
diff --git a/tools/hv/Makefile b/tools/hv/Makefile
index 5db5e62cebda..b57143d9459c 100644
--- a/tools/hv/Makefile
+++ b/tools/hv/Makefile
@@ -1,28 +1,55 @@
# SPDX-License-Identifier: GPL-2.0
# Makefile for Hyper-V tools
-
-WARNINGS = -Wall -Wextra
-CFLAGS = $(WARNINGS) -g $(shell getconf LFS_CFLAGS)
-
-CFLAGS += -D__EXPORTED_HEADERS__ -I../../include/uapi -I../../include
+include ../scripts/Makefile.include
sbindir ?= /usr/sbin
libexecdir ?= /usr/libexec
sharedstatedir ?= /var/lib
-ALL_PROGRAMS := hv_kvp_daemon hv_vss_daemon hv_fcopy_daemon
+ifeq ($(srctree),)
+srctree := $(patsubst %/,%,$(dir $(CURDIR)))
+srctree := $(patsubst %/,%,$(dir $(srctree)))
+endif
+
+# Do not use make's built-in rules
+# (this improves performance and avoids hard-to-debug behaviour);
+MAKEFLAGS += -r
+
+override CFLAGS += -O2 -Wall -g -D_GNU_SOURCE -I$(OUTPUT)include
+
+ALL_TARGETS := hv_kvp_daemon hv_vss_daemon hv_fcopy_daemon
+ALL_PROGRAMS := $(patsubst %,$(OUTPUT)%,$(ALL_TARGETS))
ALL_SCRIPTS := hv_get_dhcp_info.sh hv_get_dns_info.sh hv_set_ifconfig.sh
all: $(ALL_PROGRAMS)
-%: %.c
- $(CC) $(CFLAGS) -o $@ $^
+export srctree OUTPUT CC LD CFLAGS
+include $(srctree)/tools/build/Makefile.include
+
+HV_KVP_DAEMON_IN := $(OUTPUT)hv_kvp_daemon-in.o
+$(HV_KVP_DAEMON_IN): FORCE
+ $(Q)$(MAKE) $(build)=hv_kvp_daemon
+$(OUTPUT)hv_kvp_daemon: $(HV_KVP_DAEMON_IN)
+ $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@
+
+HV_VSS_DAEMON_IN := $(OUTPUT)hv_vss_daemon-in.o
+$(HV_VSS_DAEMON_IN): FORCE
+ $(Q)$(MAKE) $(build)=hv_vss_daemon
+$(OUTPUT)hv_vss_daemon: $(HV_VSS_DAEMON_IN)
+ $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@
+
+HV_FCOPY_DAEMON_IN := $(OUTPUT)hv_fcopy_daemon-in.o
+$(HV_FCOPY_DAEMON_IN): FORCE
+ $(Q)$(MAKE) $(build)=hv_fcopy_daemon
+$(OUTPUT)hv_fcopy_daemon: $(HV_FCOPY_DAEMON_IN)
+ $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@
clean:
- $(RM) hv_kvp_daemon hv_vss_daemon hv_fcopy_daemon
+ rm -f $(ALL_PROGRAMS)
+ find $(if $(OUTPUT),$(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete
-install: all
+install: $(ALL_PROGRAMS)
install -d -m 755 $(DESTDIR)$(sbindir); \
install -d -m 755 $(DESTDIR)$(libexecdir)/hypervkvpd; \
install -d -m 755 $(DESTDIR)$(sharedstatedir); \
@@ -33,3 +60,7 @@ install: all
for script in $(ALL_SCRIPTS); do \
install $$script -m 755 $(DESTDIR)$(libexecdir)/hypervkvpd/$${script%.sh}; \
done
+
+FORCE:
+
+.PHONY: all install clean FORCE prepare
--
2.20.1
^ permalink raw reply related
* [PATCH v4 0/2] Drivers: hv: Move Hyper-V clock/timer code to separate clocksource driver
From: Michael Kelley @ 2019-06-28 18:33 UTC (permalink / raw)
To: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
x86@kernel.org
Cc: Michael Kelley, will.deacon@arm.com, catalin.marinas@arm.com,
mark.rutland@arm.com, linux-arm-kernel@lists.infradead.org,
gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
linux-hyperv@vger.kernel.org, olaf@aepfle.de, apw@canonical.com,
vkuznets, jasowang@redhat.com, marcelo.cerri@canonical.com,
Sunil Muthuswamy, KY Srinivasan, sashal@kernel.org,
vincenzo.frascino@arm.com, linux-arch@vger.kernel.org,
linux-mips@vger.kernel.org, linux-kselftest@vger.kernel.org,
arnd@arndb.de, linux@armlinux.org.uk, ralf@linux-mips.org,
paul.burton@mips.com, daniel.lezcano@linaro.org,
salyzyn@android.com, pcc@google.com, shuah@kernel.org,
0x7f454c46@gmail.com, linux@rasmusvillemoes.dk,
huw@codeweavers.com, sfr@canb.auug.org.au, pbonzini@redhat.com,
rkrcmar@redhat.com, kvm@vger.kernel.org
This patch series moves Hyper-V clock/timer code to a separate Hyper-V
clocksource driver. Previously, Hyper-V clock/timer code and data
structures were mixed in with other Hyper-V code in the ISA independent
drivers/hv code as well as in ISA dependent code. The new Hyper-V
clocksource driver is ISA independent, with a just few dependencies on
ISA specific functions. The patch series does not change any behavior
or functionality -- it only reorganizes the existing code and fixes up
the linkages. A few places outside of Hyper-V code are fixed up to use
the new #include file structure.
This restructuring is in response to Marc Zyngier's review comments
on supporting Hyper-V running on ARM64, and is a good idea in general.
It increases the amount of code shared between the x86 and ARM64
architectures, and reduces the size of the new code for supporting
Hyper-V on ARM64. A new version of the Hyper-V on ARM64 patches will
follow once this clocksource restructuring is accepted.
The code is diff'ed against the upstream tip tree:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers/vdso
Changes in v4:
* Revised commit messages
* Rebased to upstream tip tree
Changes in v3:
* Removed boolean argument to hv_init_clocksource(). Always call
sched_clock_register, which is needed on ARM64 but a no-op on x86.
* Removed separate cpuhp setup in hv_stimer_alloc() and instead
directly call hv_stimer_init() and hv_stimer_cleanup() from
corresponding VMbus functions. This more closely matches original
code and avoids clocksource stop/restart problems on ARM64 when
VMbus code denies CPU offlining request.
Changes in v2:
* Revised commit short descriptions so the distinction between
the first and second patches is clearer [GregKH]
* Renamed new clocksource driver files and functions to use
existing "timer" and "stimer" names instead of introducing
"syntimer". [Vitaly Kuznetsov]
* Introduced CONFIG_HYPER_TIMER to fix build problem when
CONFIG_HYPERV=m [Vitaly Kuznetsov]
* Added "Suggested-by: Marc Zyngier"
Michael Kelley (2):
Drivers: hv: Create Hyper-V clocksource driver from existing
clockevents code
Drivers: hv: Move Hyper-V clocksource code to new clocksource driver
MAINTAINERS | 2 +
arch/x86/entry/vdso/vma.c | 2 +-
arch/x86/hyperv/hv_init.c | 91 +--------
arch/x86/include/asm/hyperv-tlfs.h | 6 +
arch/x86/include/asm/mshyperv.h | 81 ++------
arch/x86/include/asm/vdso/gettimeofday.h | 2 +-
arch/x86/kernel/cpu/mshyperv.c | 2 +
arch/x86/kvm/x86.c | 1 +
drivers/clocksource/Makefile | 1 +
drivers/clocksource/hyperv_timer.c | 321 +++++++++++++++++++++++++++++++
drivers/hv/Kconfig | 3 +
drivers/hv/hv.c | 156 +--------------
drivers/hv/hyperv_vmbus.h | 3 -
drivers/hv/vmbus_drv.c | 42 ++--
include/clocksource/hyperv_timer.h | 105 ++++++++++
15 files changed, 483 insertions(+), 335 deletions(-)
create mode 100644 drivers/clocksource/hyperv_timer.c
create mode 100644 include/clocksource/hyperv_timer.h
--
1.8.3.1
^ permalink raw reply
* [PATCH v4 1/2] Drivers: hv: Create Hyper-V clocksource driver from existing clockevents code
From: Michael Kelley @ 2019-06-28 18:33 UTC (permalink / raw)
To: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
x86@kernel.org
Cc: Michael Kelley, will.deacon@arm.com, catalin.marinas@arm.com,
mark.rutland@arm.com, linux-arm-kernel@lists.infradead.org,
gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
linux-hyperv@vger.kernel.org, olaf@aepfle.de, apw@canonical.com,
vkuznets, jasowang@redhat.com, marcelo.cerri@canonical.com,
Sunil Muthuswamy, KY Srinivasan, sashal@kernel.org,
vincenzo.frascino@arm.com, linux-arch@vger.kernel.org,
linux-mips@vger.kernel.org, linux-kselftest@vger.kernel.org,
arnd@arndb.de, linux@armlinux.org.uk, ralf@linux-mips.org,
paul.burton@mips.com, daniel.lezcano@linaro.org,
salyzyn@android.com, pcc@google.com, shuah@kernel.org,
0x7f454c46@gmail.com, linux@rasmusvillemoes.dk,
huw@codeweavers.com, sfr@canb.auug.org.au, pbonzini@redhat.com,
rkrcmar@redhat.com, kvm@vger.kernel.org
In-Reply-To: <1561746758-23216-1-git-send-email-mikelley@microsoft.com>
Hyper-V clock/timer code and data structures are currently mixed
in with other code in the ISA independent drivers/hv directory as
well as the ISA dependent Hyper-V code under arch/x86. Consolidate
this code and data structures into a Hyper-V clocksource driver to
better follow the Linux model. In doing so, separate out the ISA
dependent portions so the new clocksource driver works for x86 and
for the in-process Hyper-V on ARM64 code.
To start, move the existing clockevents code to create the
new clocksource driver. Update the VMbus driver to call
initialization and cleanup routines since the Hyper-V
synthetic timers are not independently enumerated in ACPI.
No behavior is changed and no new functionality is added.
Suggested-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
---
MAINTAINERS | 2 +
arch/x86/include/asm/hyperv-tlfs.h | 6 ++
arch/x86/kernel/cpu/mshyperv.c | 2 +
drivers/clocksource/Makefile | 1 +
drivers/clocksource/hyperv_timer.c | 191 +++++++++++++++++++++++++++++++++++++
drivers/hv/Kconfig | 3 +
drivers/hv/hv.c | 156 +-----------------------------
drivers/hv/hyperv_vmbus.h | 3 -
drivers/hv/vmbus_drv.c | 42 ++++----
include/clocksource/hyperv_timer.h | 27 ++++++
10 files changed, 258 insertions(+), 175 deletions(-)
create mode 100644 drivers/clocksource/hyperv_timer.c
create mode 100644 include/clocksource/hyperv_timer.h
diff --git a/MAINTAINERS b/MAINTAINERS
index a281297..bfde42a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7313,6 +7313,7 @@ F: arch/x86/include/asm/trace/hyperv.h
F: arch/x86/include/asm/hyperv-tlfs.h
F: arch/x86/kernel/cpu/mshyperv.c
F: arch/x86/hyperv
+F: drivers/clocksource/hyperv_timer.c
F: drivers/hid/hid-hyperv.c
F: drivers/hv/
F: drivers/input/serio/hyperv-keyboard.c
@@ -7323,6 +7324,7 @@ F: drivers/uio/uio_hv_generic.c
F: drivers/video/fbdev/hyperv_fb.c
F: drivers/iommu/hyperv_iommu.c
F: net/vmw_vsock/hyperv_transport.c
+F: include/clocksource/hyperv_timer.h
F: include/linux/hyperv.h
F: include/uapi/linux/hyperv.h
F: tools/hv/
diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index cdf44aa..af78cd7 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/arch/x86/include/asm/hyperv-tlfs.h
@@ -401,6 +401,12 @@ enum HV_GENERIC_SET_FORMAT {
#define HV_STATUS_INVALID_CONNECTION_ID 18
#define HV_STATUS_INSUFFICIENT_BUFFERS 19
+/*
+ * The Hyper-V TimeRefCount register and the TSC
+ * page provide a guest VM clock with 100ns tick rate
+ */
+#define HV_CLOCK_HZ (NSEC_PER_SEC/100)
+
typedef struct _HV_REFERENCE_TSC_PAGE {
__u32 tsc_sequence;
__u32 res1;
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 7df29f0..b822fa6 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -17,6 +17,7 @@
#include <linux/irq.h>
#include <linux/kexec.h>
#include <linux/i8253.h>
+#include <linux/random.h>
#include <asm/processor.h>
#include <asm/hypervisor.h>
#include <asm/hyperv-tlfs.h>
@@ -80,6 +81,7 @@ __visible void __irq_entry hv_stimer0_vector_handler(struct pt_regs *regs)
inc_irq_stat(hyperv_stimer0_count);
if (hv_stimer0_handler)
hv_stimer0_handler();
+ add_interrupt_randomness(HYPERV_STIMER0_VECTOR, 0);
ack_APIC_irq();
exiting_irq();
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 236858f..2b65c5f 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -84,3 +84,4 @@ obj-$(CONFIG_ATCPIT100_TIMER) += timer-atcpit100.o
obj-$(CONFIG_RISCV_TIMER) += timer-riscv.o
obj-$(CONFIG_CSKY_MP_TIMER) += timer-mp-csky.o
obj-$(CONFIG_GX6605S_TIMER) += timer-gx6605s.o
+obj-$(CONFIG_HYPERV_TIMER) += hyperv_timer.o
diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c
new file mode 100644
index 0000000..30615f3
--- /dev/null
+++ b/drivers/clocksource/hyperv_timer.c
@@ -0,0 +1,191 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Clocksource driver for the synthetic counter and timers
+ * provided by the Hyper-V hypervisor to guest VMs, as described
+ * in the Hyper-V Top Level Functional Spec (TLFS). This driver
+ * is instruction set architecture independent.
+ *
+ * Copyright (C) 2019, Microsoft, Inc.
+ *
+ * Author: Michael Kelley <mikelley@microsoft.com>
+ */
+
+#include <linux/percpu.h>
+#include <linux/cpumask.h>
+#include <linux/clockchips.h>
+#include <linux/mm.h>
+#include <clocksource/hyperv_timer.h>
+#include <asm/hyperv-tlfs.h>
+#include <asm/mshyperv.h>
+
+static struct clock_event_device __percpu *hv_clock_event;
+
+/*
+ * If false, we're using the old mechanism for stimer0 interrupts
+ * where it sends a VMbus message when it expires. The old
+ * mechanism is used when running on older versions of Hyper-V
+ * that don't support Direct Mode. While Hyper-V provides
+ * four stimer's per CPU, Linux uses only stimer0.
+ */
+static bool direct_mode_enabled;
+
+static int stimer0_irq;
+static int stimer0_vector;
+static int stimer0_message_sint;
+
+/*
+ * ISR for when stimer0 is operating in Direct Mode. Direct Mode
+ * does not use VMbus or any VMbus messages, so process here and not
+ * in the VMbus driver code.
+ */
+void hv_stimer0_isr(void)
+{
+ struct clock_event_device *ce;
+
+ ce = this_cpu_ptr(hv_clock_event);
+ ce->event_handler(ce);
+}
+EXPORT_SYMBOL_GPL(hv_stimer0_isr);
+
+static int hv_ce_set_next_event(unsigned long delta,
+ struct clock_event_device *evt)
+{
+ u64 current_tick;
+
+ WARN_ON(!clockevent_state_oneshot(evt));
+
+ current_tick = hyperv_cs->read(NULL);
+ current_tick += delta;
+ hv_init_timer(0, current_tick);
+ return 0;
+}
+
+static int hv_ce_shutdown(struct clock_event_device *evt)
+{
+ hv_init_timer(0, 0);
+ hv_init_timer_config(0, 0);
+ if (direct_mode_enabled)
+ hv_disable_stimer0_percpu_irq(stimer0_irq);
+
+ return 0;
+}
+
+static int hv_ce_set_oneshot(struct clock_event_device *evt)
+{
+ union hv_stimer_config timer_cfg;
+
+ timer_cfg.as_uint64 = 0;
+ timer_cfg.enable = 1;
+ timer_cfg.auto_enable = 1;
+ if (direct_mode_enabled) {
+ /*
+ * When it expires, the timer will directly interrupt
+ * on the specified hardware vector/IRQ.
+ */
+ timer_cfg.direct_mode = 1;
+ timer_cfg.apic_vector = stimer0_vector;
+ hv_enable_stimer0_percpu_irq(stimer0_irq);
+ } else {
+ /*
+ * When it expires, the timer will generate a VMbus message,
+ * to be handled by the normal VMbus interrupt handler.
+ */
+ timer_cfg.direct_mode = 0;
+ timer_cfg.sintx = stimer0_message_sint;
+ }
+ hv_init_timer_config(0, timer_cfg.as_uint64);
+ return 0;
+}
+
+/*
+ * hv_stimer_init - Per-cpu initialization of the clockevent
+ */
+int hv_stimer_init(unsigned int cpu)
+{
+ struct clock_event_device *ce;
+
+ if (ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE) {
+ ce = per_cpu_ptr(hv_clock_event, cpu);
+ ce->name = "Hyper-V clockevent";
+ ce->features = CLOCK_EVT_FEAT_ONESHOT;
+ ce->cpumask = cpumask_of(cpu);
+ ce->rating = 1000;
+ ce->set_state_shutdown = hv_ce_shutdown;
+ ce->set_state_oneshot = hv_ce_set_oneshot;
+ ce->set_next_event = hv_ce_set_next_event;
+
+ clockevents_config_and_register(ce,
+ HV_CLOCK_HZ,
+ HV_MIN_DELTA_TICKS,
+ HV_MAX_MAX_DELTA_TICKS);
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(hv_stimer_init);
+
+/*
+ * hv_stimer_cleanup - Per-cpu cleanup of the clockevent
+ */
+int hv_stimer_cleanup(unsigned int cpu)
+{
+ struct clock_event_device *ce;
+
+ /* Turn off clockevent device */
+ if (ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE) {
+ ce = per_cpu_ptr(hv_clock_event, cpu);
+ clockevents_unbind_device(ce, cpu);
+ hv_ce_shutdown(ce);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(hv_stimer_cleanup);
+
+/* hv_stimer_alloc - Global initialization of the clockevent and stimer0 */
+int hv_stimer_alloc(int sint)
+{
+ hv_clock_event = alloc_percpu(struct clock_event_device);
+ if (!hv_clock_event)
+ return -ENOMEM;
+
+ direct_mode_enabled = ms_hyperv.misc_features &
+ HV_STIMER_DIRECT_MODE_AVAILABLE;
+ if (direct_mode_enabled &&
+ hv_setup_stimer0_irq(&stimer0_irq, &stimer0_vector,
+ hv_stimer0_isr)) {
+ free_percpu(hv_clock_event);
+ return -EINVAL;
+ }
+
+ stimer0_message_sint = sint;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(hv_stimer_alloc);
+
+/* hv_stimer_free - Free global resources allocated by hv_stimer_alloc() */
+void hv_stimer_free(void)
+{
+ if (direct_mode_enabled)
+ hv_remove_stimer0_irq(stimer0_irq);
+ free_percpu(hv_clock_event);
+}
+EXPORT_SYMBOL_GPL(hv_stimer_free);
+
+/*
+ * Do a global cleanup of clockevents for the cases of kexec and
+ * vmbus exit
+ */
+void hv_stimer_global_cleanup(void)
+{
+ int cpu;
+ struct clock_event_device *ce;
+
+ if (ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE)
+ for_each_present_cpu(cpu) {
+ ce = per_cpu_ptr(hv_clock_event, cpu);
+ clockevents_unbind_device(ce, cpu);
+ }
+ hv_stimer_free();
+}
+EXPORT_SYMBOL_GPL(hv_stimer_global_cleanup);
diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig
index 1c1a251..c423e57 100644
--- a/drivers/hv/Kconfig
+++ b/drivers/hv/Kconfig
@@ -10,6 +10,9 @@ config HYPERV
Select this option to run Linux as a Hyper-V client operating
system.
+config HYPERV_TIMER
+ def_bool HYPERV
+
config HYPERV_TSCPAGE
def_bool HYPERV && X86_64
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index a1ea482..6188fb7 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -16,6 +16,7 @@
#include <linux/version.h>
#include <linux/random.h>
#include <linux/clockchips.h>
+#include <clocksource/hyperv_timer.h>
#include <asm/mshyperv.h>
#include "hyperv_vmbus.h"
@@ -23,21 +24,6 @@
struct hv_context hv_context;
/*
- * If false, we're using the old mechanism for stimer0 interrupts
- * where it sends a VMbus message when it expires. The old
- * mechanism is used when running on older versions of Hyper-V
- * that don't support Direct Mode. While Hyper-V provides
- * four stimer's per CPU, Linux uses only stimer0.
- */
-static bool direct_mode_enabled;
-static int stimer0_irq;
-static int stimer0_vector;
-
-#define HV_TIMER_FREQUENCY (10 * 1000 * 1000) /* 100ns period */
-#define HV_MAX_MAX_DELTA_TICKS 0xffffffff
-#define HV_MIN_DELTA_TICKS 1
-
-/*
* hv_init - Main initialization routine.
*
* This routine must be called before any other routines in here are called
@@ -47,9 +33,6 @@ int hv_init(void)
hv_context.cpu_context = alloc_percpu(struct hv_per_cpu_context);
if (!hv_context.cpu_context)
return -ENOMEM;
-
- direct_mode_enabled = ms_hyperv.misc_features &
- HV_STIMER_DIRECT_MODE_AVAILABLE;
return 0;
}
@@ -88,89 +71,6 @@ int hv_post_message(union hv_connection_id connection_id,
return status & 0xFFFF;
}
-/*
- * ISR for when stimer0 is operating in Direct Mode. Direct Mode
- * does not use VMbus or any VMbus messages, so process here and not
- * in the VMbus driver code.
- */
-
-static void hv_stimer0_isr(void)
-{
- struct hv_per_cpu_context *hv_cpu;
-
- hv_cpu = this_cpu_ptr(hv_context.cpu_context);
- hv_cpu->clk_evt->event_handler(hv_cpu->clk_evt);
- add_interrupt_randomness(stimer0_vector, 0);
-}
-
-static int hv_ce_set_next_event(unsigned long delta,
- struct clock_event_device *evt)
-{
- u64 current_tick;
-
- WARN_ON(!clockevent_state_oneshot(evt));
-
- current_tick = hyperv_cs->read(NULL);
- current_tick += delta;
- hv_init_timer(0, current_tick);
- return 0;
-}
-
-static int hv_ce_shutdown(struct clock_event_device *evt)
-{
- hv_init_timer(0, 0);
- hv_init_timer_config(0, 0);
- if (direct_mode_enabled)
- hv_disable_stimer0_percpu_irq(stimer0_irq);
-
- return 0;
-}
-
-static int hv_ce_set_oneshot(struct clock_event_device *evt)
-{
- union hv_stimer_config timer_cfg;
-
- timer_cfg.as_uint64 = 0;
- timer_cfg.enable = 1;
- timer_cfg.auto_enable = 1;
- if (direct_mode_enabled) {
- /*
- * When it expires, the timer will directly interrupt
- * on the specified hardware vector/IRQ.
- */
- timer_cfg.direct_mode = 1;
- timer_cfg.apic_vector = stimer0_vector;
- hv_enable_stimer0_percpu_irq(stimer0_irq);
- } else {
- /*
- * When it expires, the timer will generate a VMbus message,
- * to be handled by the normal VMbus interrupt handler.
- */
- timer_cfg.direct_mode = 0;
- timer_cfg.sintx = VMBUS_MESSAGE_SINT;
- }
- hv_init_timer_config(0, timer_cfg.as_uint64);
- return 0;
-}
-
-static void hv_init_clockevent_device(struct clock_event_device *dev, int cpu)
-{
- dev->name = "Hyper-V clockevent";
- dev->features = CLOCK_EVT_FEAT_ONESHOT;
- dev->cpumask = cpumask_of(cpu);
- dev->rating = 1000;
- /*
- * Avoid settint dev->owner = THIS_MODULE deliberately as doing so will
- * result in clockevents_config_and_register() taking additional
- * references to the hv_vmbus module making it impossible to unload.
- */
-
- dev->set_state_shutdown = hv_ce_shutdown;
- dev->set_state_oneshot = hv_ce_set_oneshot;
- dev->set_next_event = hv_ce_set_next_event;
-}
-
-
int hv_synic_alloc(void)
{
int cpu;
@@ -199,14 +99,6 @@ int hv_synic_alloc(void)
tasklet_init(&hv_cpu->msg_dpc,
vmbus_on_msg_dpc, (unsigned long) hv_cpu);
- hv_cpu->clk_evt = kzalloc(sizeof(struct clock_event_device),
- GFP_KERNEL);
- if (hv_cpu->clk_evt == NULL) {
- pr_err("Unable to allocate clock event device\n");
- goto err;
- }
- hv_init_clockevent_device(hv_cpu->clk_evt, cpu);
-
hv_cpu->synic_message_page =
(void *)get_zeroed_page(GFP_ATOMIC);
if (hv_cpu->synic_message_page == NULL) {
@@ -229,11 +121,6 @@ int hv_synic_alloc(void)
INIT_LIST_HEAD(&hv_cpu->chan_list);
}
- if (direct_mode_enabled &&
- hv_setup_stimer0_irq(&stimer0_irq, &stimer0_vector,
- hv_stimer0_isr))
- goto err;
-
return 0;
err:
/*
@@ -252,7 +139,6 @@ void hv_synic_free(void)
struct hv_per_cpu_context *hv_cpu
= per_cpu_ptr(hv_context.cpu_context, cpu);
- kfree(hv_cpu->clk_evt);
free_page((unsigned long)hv_cpu->synic_event_page);
free_page((unsigned long)hv_cpu->synic_message_page);
free_page((unsigned long)hv_cpu->post_msg_page);
@@ -311,36 +197,9 @@ int hv_synic_init(unsigned int cpu)
hv_set_synic_state(sctrl.as_uint64);
- /*
- * Register the per-cpu clockevent source.
- */
- if (ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE)
- clockevents_config_and_register(hv_cpu->clk_evt,
- HV_TIMER_FREQUENCY,
- HV_MIN_DELTA_TICKS,
- HV_MAX_MAX_DELTA_TICKS);
- return 0;
-}
-
-/*
- * hv_synic_clockevents_cleanup - Cleanup clockevent devices
- */
-void hv_synic_clockevents_cleanup(void)
-{
- int cpu;
+ hv_stimer_init(cpu);
- if (!(ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE))
- return;
-
- if (direct_mode_enabled)
- hv_remove_stimer0_irq(stimer0_irq);
-
- for_each_present_cpu(cpu) {
- struct hv_per_cpu_context *hv_cpu
- = per_cpu_ptr(hv_context.cpu_context, cpu);
-
- clockevents_unbind_device(hv_cpu->clk_evt, cpu);
- }
+ return 0;
}
/*
@@ -388,14 +247,7 @@ int hv_synic_cleanup(unsigned int cpu)
if (channel_found && vmbus_connection.conn_state == CONNECTED)
return -EBUSY;
- /* Turn off clockevent device */
- if (ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE) {
- struct hv_per_cpu_context *hv_cpu
- = this_cpu_ptr(hv_context.cpu_context);
-
- clockevents_unbind_device(hv_cpu->clk_evt, cpu);
- hv_ce_shutdown(hv_cpu->clk_evt);
- }
+ hv_stimer_cleanup(cpu);
hv_get_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index b8e1ff0..362e70e 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -138,7 +138,6 @@ struct hv_per_cpu_context {
* per-cpu list of the channels based on their CPU affinity.
*/
struct list_head chan_list;
- struct clock_event_device *clk_evt;
};
struct hv_context {
@@ -176,8 +175,6 @@ extern int hv_post_message(union hv_connection_id connection_id,
extern int hv_synic_cleanup(unsigned int cpu);
-extern void hv_synic_clockevents_cleanup(void);
-
/* Interface */
void hv_ringbuffer_pre_init(struct vmbus_channel *channel);
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 92b1874..72d5a7c 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -30,6 +30,7 @@
#include <linux/kdebug.h>
#include <linux/efi.h>
#include <linux/random.h>
+#include <clocksource/hyperv_timer.h>
#include "hyperv_vmbus.h"
struct vmbus_dynid {
@@ -955,17 +956,6 @@ static void vmbus_onmessage_work(struct work_struct *work)
kfree(ctx);
}
-static void hv_process_timer_expiration(struct hv_message *msg,
- struct hv_per_cpu_context *hv_cpu)
-{
- struct clock_event_device *dev = hv_cpu->clk_evt;
-
- if (dev->event_handler)
- dev->event_handler(dev);
-
- vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
-}
-
void vmbus_on_msg_dpc(unsigned long data)
{
struct hv_per_cpu_context *hv_cpu = (void *)data;
@@ -1159,9 +1149,10 @@ static void vmbus_isr(void)
/* Check if there are actual msgs to be processed */
if (msg->header.message_type != HVMSG_NONE) {
- if (msg->header.message_type == HVMSG_TIMER_EXPIRED)
- hv_process_timer_expiration(msg, hv_cpu);
- else
+ if (msg->header.message_type == HVMSG_TIMER_EXPIRED) {
+ hv_stimer0_isr();
+ vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
+ } else
tasklet_schedule(&hv_cpu->msg_dpc);
}
@@ -1263,14 +1254,19 @@ static int vmbus_bus_init(void)
ret = hv_synic_alloc();
if (ret)
goto err_alloc;
+
+ ret = hv_stimer_alloc(VMBUS_MESSAGE_SINT);
+ if (ret < 0)
+ goto err_alloc;
+
/*
- * Initialize the per-cpu interrupt state and
- * connect to the host.
+ * Initialize the per-cpu interrupt state and stimer state.
+ * Then connect to the host.
*/
ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hyperv/vmbus:online",
hv_synic_init, hv_synic_cleanup);
if (ret < 0)
- goto err_alloc;
+ goto err_cpuhp;
hyperv_cpuhp_online = ret;
ret = vmbus_connect();
@@ -1318,6 +1314,8 @@ static int vmbus_bus_init(void)
err_connect:
cpuhp_remove_state(hyperv_cpuhp_online);
+err_cpuhp:
+ hv_stimer_free();
err_alloc:
hv_synic_free();
hv_remove_vmbus_irq();
@@ -2064,7 +2062,7 @@ static int vmbus_acpi_add(struct acpi_device *device)
static void hv_kexec_handler(void)
{
- hv_synic_clockevents_cleanup();
+ hv_stimer_global_cleanup();
vmbus_initiate_unload(false);
vmbus_connection.conn_state = DISCONNECTED;
/* Make sure conn_state is set as hv_synic_cleanup checks for it */
@@ -2075,6 +2073,8 @@ static void hv_kexec_handler(void)
static void hv_crash_handler(struct pt_regs *regs)
{
+ int cpu;
+
vmbus_initiate_unload(true);
/*
* In crash handler we can't schedule synic cleanup for all CPUs,
@@ -2082,7 +2082,9 @@ static void hv_crash_handler(struct pt_regs *regs)
* for kdump.
*/
vmbus_connection.conn_state = DISCONNECTED;
- hv_synic_cleanup(smp_processor_id());
+ cpu = smp_processor_id();
+ hv_stimer_cleanup(cpu);
+ hv_synic_cleanup(cpu);
hyperv_cleanup();
};
@@ -2131,7 +2133,7 @@ static void __exit vmbus_exit(void)
hv_remove_kexec_handler();
hv_remove_crash_handler();
vmbus_connection.conn_state = DISCONNECTED;
- hv_synic_clockevents_cleanup();
+ hv_stimer_global_cleanup();
vmbus_disconnect();
hv_remove_vmbus_irq();
for_each_online_cpu(cpu) {
diff --git a/include/clocksource/hyperv_timer.h b/include/clocksource/hyperv_timer.h
new file mode 100644
index 0000000..ba5dc17
--- /dev/null
+++ b/include/clocksource/hyperv_timer.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Definitions for the clocksource provided by the Hyper-V
+ * hypervisor to guest VMs, as described in the Hyper-V Top
+ * Level Functional Spec (TLFS).
+ *
+ * Copyright (C) 2019, Microsoft, Inc.
+ *
+ * Author: Michael Kelley <mikelley@microsoft.com>
+ */
+
+#ifndef __CLKSOURCE_HYPERV_TIMER_H
+#define __CLKSOURCE_HYPERV_TIMER_H
+
+#define HV_MAX_MAX_DELTA_TICKS 0xffffffff
+#define HV_MIN_DELTA_TICKS 1
+
+/* Routines called by the VMbus driver */
+extern int hv_stimer_alloc(int sint);
+extern void hv_stimer_free(void);
+extern int hv_stimer_init(unsigned int cpu);
+extern int hv_stimer_cleanup(unsigned int cpu);
+extern void hv_stimer_global_cleanup(void);
+extern void hv_stimer0_isr(void);
+
+#endif
--
1.8.3.1
^ permalink raw reply related
* [PATCH v4 2/2] Drivers: hv: Move Hyper-V clocksource code to new clocksource driver
From: Michael Kelley @ 2019-06-28 18:34 UTC (permalink / raw)
To: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
x86@kernel.org
Cc: Michael Kelley, will.deacon@arm.com, catalin.marinas@arm.com,
mark.rutland@arm.com, linux-arm-kernel@lists.infradead.org,
gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
linux-hyperv@vger.kernel.org, olaf@aepfle.de, apw@canonical.com,
vkuznets, jasowang@redhat.com, marcelo.cerri@canonical.com,
Sunil Muthuswamy, KY Srinivasan, sashal@kernel.org,
vincenzo.frascino@arm.com, linux-arch@vger.kernel.org,
linux-mips@vger.kernel.org, linux-kselftest@vger.kernel.org,
arnd@arndb.de, linux@armlinux.org.uk, ralf@linux-mips.org,
paul.burton@mips.com, daniel.lezcano@linaro.org,
salyzyn@android.com, pcc@google.com, shuah@kernel.org,
0x7f454c46@gmail.com, linux@rasmusvillemoes.dk,
huw@codeweavers.com, sfr@canb.auug.org.au, pbonzini@redhat.com,
rkrcmar@redhat.com, kvm@vger.kernel.org
In-Reply-To: <1561746758-23216-1-git-send-email-mikelley@microsoft.com>
Continue consolidating Hyper-V clock and timer code into an ISA
independent Hyper-V clocksource driver. Move the existing clocksource
code under drivers/hv and arch/x86 to the new clocksource driver
while separating out the ISA dependencies. Update Hyper-V
initialization to call initialization and cleanup routines since the
Hyper-V synthetic clock is not independently enumerated in ACPI.
Update Hyper-V clocksource users in KVM and VDSO to get definitions
from a new include file.
No behavior is changed and no new functionality is added.
Suggested-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
---
arch/x86/entry/vdso/vma.c | 2 +-
arch/x86/hyperv/hv_init.c | 91 +---------------------
arch/x86/include/asm/mshyperv.h | 81 +++----------------
arch/x86/include/asm/vdso/gettimeofday.h | 2 +-
arch/x86/kvm/x86.c | 1 +
drivers/clocksource/hyperv_timer.c | 130 +++++++++++++++++++++++++++++++
include/clocksource/hyperv_timer.h | 78 +++++++++++++++++++
7 files changed, 225 insertions(+), 160 deletions(-)
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 8db1f59..349a61d 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -22,7 +22,7 @@
#include <asm/page.h>
#include <asm/desc.h>
#include <asm/cpufeature.h>
-#include <asm/mshyperv.h>
+#include <clocksource/hyperv_timer.h>
#if defined(CONFIG_X86_64)
unsigned int __read_mostly vdso64_enabled = 1;
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 1608050..0e033ef 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -17,64 +17,13 @@
#include <linux/version.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
-#include <linux/clockchips.h>
#include <linux/hyperv.h>
#include <linux/slab.h>
#include <linux/cpuhotplug.h>
-
-#ifdef CONFIG_HYPERV_TSCPAGE
-
-static struct ms_hyperv_tsc_page *tsc_pg;
-
-struct ms_hyperv_tsc_page *hv_get_tsc_page(void)
-{
- return tsc_pg;
-}
-EXPORT_SYMBOL_GPL(hv_get_tsc_page);
-
-static u64 read_hv_clock_tsc(struct clocksource *arg)
-{
- u64 current_tick = hv_read_tsc_page(tsc_pg);
-
- if (current_tick == U64_MAX)
- rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
-
- return current_tick;
-}
-
-static struct clocksource hyperv_cs_tsc = {
- .name = "hyperv_clocksource_tsc_page",
- .rating = 400,
- .read = read_hv_clock_tsc,
- .mask = CLOCKSOURCE_MASK(64),
- .flags = CLOCK_SOURCE_IS_CONTINUOUS,
-};
-#endif
-
-static u64 read_hv_clock_msr(struct clocksource *arg)
-{
- u64 current_tick;
- /*
- * Read the partition counter to get the current tick count. This count
- * is set to 0 when the partition is created and is incremented in
- * 100 nanosecond units.
- */
- rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
- return current_tick;
-}
-
-static struct clocksource hyperv_cs_msr = {
- .name = "hyperv_clocksource_msr",
- .rating = 400,
- .read = read_hv_clock_msr,
- .mask = CLOCKSOURCE_MASK(64),
- .flags = CLOCK_SOURCE_IS_CONTINUOUS,
-};
+#include <clocksource/hyperv_timer.h>
void *hv_hypercall_pg;
EXPORT_SYMBOL_GPL(hv_hypercall_pg);
-struct clocksource *hyperv_cs;
-EXPORT_SYMBOL_GPL(hyperv_cs);
u32 *hv_vp_index;
EXPORT_SYMBOL_GPL(hv_vp_index);
@@ -343,42 +292,8 @@ void __init hyperv_init(void)
x86_init.pci.arch_init = hv_pci_init;
- /*
- * Register Hyper-V specific clocksource.
- */
-#ifdef CONFIG_HYPERV_TSCPAGE
- if (ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE) {
- union hv_x64_msr_hypercall_contents tsc_msr;
-
- tsc_pg = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL);
- if (!tsc_pg)
- goto register_msr_cs;
-
- hyperv_cs = &hyperv_cs_tsc;
-
- rdmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
-
- tsc_msr.enable = 1;
- tsc_msr.guest_physical_address = vmalloc_to_pfn(tsc_pg);
-
- wrmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
-
- hyperv_cs_tsc.archdata.vclock_mode = VCLOCK_HVCLOCK;
-
- clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100);
- return;
- }
-register_msr_cs:
-#endif
- /*
- * For 32 bit guests just use the MSR based mechanism for reading
- * the partition counter.
- */
-
- hyperv_cs = &hyperv_cs_msr;
- if (ms_hyperv.features & HV_MSR_TIME_REF_COUNT_AVAILABLE)
- clocksource_register_hz(&hyperv_cs_msr, NSEC_PER_SEC/100);
-
+ /* Register Hyper-V specific clocksource */
+ hv_init_clocksource();
return;
remove_cpuhp_state:
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index cc60e61..f4fa8a9 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -105,6 +105,17 @@ static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
#define hv_get_crash_ctl(val) \
rdmsrl(HV_X64_MSR_CRASH_CTL, val)
+#define hv_get_time_ref_count(val) \
+ rdmsrl(HV_X64_MSR_TIME_REF_COUNT, val)
+
+#define hv_get_reference_tsc(val) \
+ rdmsrl(HV_X64_MSR_REFERENCE_TSC, val)
+#define hv_set_reference_tsc(val) \
+ wrmsrl(HV_X64_MSR_REFERENCE_TSC, val)
+#define hv_set_clocksource_vdso(val) \
+ ((val).archdata.vclock_mode = VCLOCK_HVCLOCK)
+#define hv_get_raw_timer() rdtsc_ordered()
+
void hyperv_callback_vector(void);
void hyperv_reenlightenment_vector(void);
#ifdef CONFIG_TRACING
@@ -133,7 +144,6 @@ static inline void hv_disable_stimer0_percpu_irq(int irq) {}
#if IS_ENABLED(CONFIG_HYPERV)
-extern struct clocksource *hyperv_cs;
extern void *hv_hypercall_pg;
extern void __percpu **hyperv_pcpu_input_arg;
@@ -387,73 +397,4 @@ static inline int hyperv_flush_guest_mapping_range(u64 as,
}
#endif /* CONFIG_HYPERV */
-#ifdef CONFIG_HYPERV_TSCPAGE
-struct ms_hyperv_tsc_page *hv_get_tsc_page(void);
-static inline u64 hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg,
- u64 *cur_tsc)
-{
- u64 scale, offset;
- u32 sequence;
-
- /*
- * The protocol for reading Hyper-V TSC page is specified in Hypervisor
- * Top-Level Functional Specification ver. 3.0 and above. To get the
- * reference time we must do the following:
- * - READ ReferenceTscSequence
- * A special '0' value indicates the time source is unreliable and we
- * need to use something else. The currently published specification
- * versions (up to 4.0b) contain a mistake and wrongly claim '-1'
- * instead of '0' as the special value, see commit c35b82ef0294.
- * - ReferenceTime =
- * ((RDTSC() * ReferenceTscScale) >> 64) + ReferenceTscOffset
- * - READ ReferenceTscSequence again. In case its value has changed
- * since our first reading we need to discard ReferenceTime and repeat
- * the whole sequence as the hypervisor was updating the page in
- * between.
- */
- do {
- sequence = READ_ONCE(tsc_pg->tsc_sequence);
- if (!sequence)
- return U64_MAX;
- /*
- * Make sure we read sequence before we read other values from
- * TSC page.
- */
- smp_rmb();
-
- scale = READ_ONCE(tsc_pg->tsc_scale);
- offset = READ_ONCE(tsc_pg->tsc_offset);
- *cur_tsc = rdtsc_ordered();
-
- /*
- * Make sure we read sequence after we read all other values
- * from TSC page.
- */
- smp_rmb();
-
- } while (READ_ONCE(tsc_pg->tsc_sequence) != sequence);
-
- return mul_u64_u64_shr(*cur_tsc, scale, 64) + offset;
-}
-
-static inline u64 hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg)
-{
- u64 cur_tsc;
-
- return hv_read_tsc_page_tsc(tsc_pg, &cur_tsc);
-}
-
-#else
-static inline struct ms_hyperv_tsc_page *hv_get_tsc_page(void)
-{
- return NULL;
-}
-
-static inline u64 hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg,
- u64 *cur_tsc)
-{
- BUG();
- return U64_MAX;
-}
-#endif
#endif
diff --git a/arch/x86/include/asm/vdso/gettimeofday.h b/arch/x86/include/asm/vdso/gettimeofday.h
index a14039a..ae91429 100644
--- a/arch/x86/include/asm/vdso/gettimeofday.h
+++ b/arch/x86/include/asm/vdso/gettimeofday.h
@@ -18,7 +18,7 @@
#include <asm/unistd.h>
#include <asm/msr.h>
#include <asm/pvclock.h>
-#include <asm/mshyperv.h>
+#include <clocksource/hyperv_timer.h>
#define __vdso_data (VVAR(_vdso_data))
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9857992..07ddb1e 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -67,6 +67,7 @@
#include <asm/mshyperv.h>
#include <asm/hypervisor.h>
#include <asm/intel_pt.h>
+#include <clocksource/hyperv_timer.h>
#define CREATE_TRACE_POINTS
#include "trace.h"
diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c
index 30615f3..274614d 100644
--- a/drivers/clocksource/hyperv_timer.c
+++ b/drivers/clocksource/hyperv_timer.c
@@ -14,6 +14,8 @@
#include <linux/percpu.h>
#include <linux/cpumask.h>
#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/sched_clock.h>
#include <linux/mm.h>
#include <clocksource/hyperv_timer.h>
#include <asm/hyperv-tlfs.h>
@@ -189,3 +191,131 @@ void hv_stimer_global_cleanup(void)
hv_stimer_free();
}
EXPORT_SYMBOL_GPL(hv_stimer_global_cleanup);
+
+/*
+ * Code and definitions for the Hyper-V clocksources. Two
+ * clocksources are defined: one that reads the Hyper-V defined MSR, and
+ * the other that uses the TSC reference page feature as defined in the
+ * TLFS. The MSR version is for compatibility with old versions of
+ * Hyper-V and 32-bit x86. The TSC reference page version is preferred.
+ */
+
+struct clocksource *hyperv_cs;
+EXPORT_SYMBOL_GPL(hyperv_cs);
+
+#ifdef CONFIG_HYPERV_TSCPAGE
+
+static struct ms_hyperv_tsc_page *tsc_pg;
+
+struct ms_hyperv_tsc_page *hv_get_tsc_page(void)
+{
+ return tsc_pg;
+}
+EXPORT_SYMBOL_GPL(hv_get_tsc_page);
+
+static u64 read_hv_sched_clock_tsc(void)
+{
+ u64 current_tick = hv_read_tsc_page(tsc_pg);
+
+ if (current_tick == U64_MAX)
+ hv_get_time_ref_count(current_tick);
+
+ return current_tick;
+}
+
+static u64 read_hv_clock_tsc(struct clocksource *arg)
+{
+ return read_hv_sched_clock_tsc();
+}
+
+static struct clocksource hyperv_cs_tsc = {
+ .name = "hyperv_clocksource_tsc_page",
+ .rating = 400,
+ .read = read_hv_clock_tsc,
+ .mask = CLOCKSOURCE_MASK(64),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+#endif
+
+static u64 read_hv_sched_clock_msr(void)
+{
+ u64 current_tick;
+ /*
+ * Read the partition counter to get the current tick count. This count
+ * is set to 0 when the partition is created and is incremented in
+ * 100 nanosecond units.
+ */
+ hv_get_time_ref_count(current_tick);
+ return current_tick;
+}
+
+static u64 read_hv_clock_msr(struct clocksource *arg)
+{
+ return read_hv_sched_clock_msr();
+}
+
+static struct clocksource hyperv_cs_msr = {
+ .name = "hyperv_clocksource_msr",
+ .rating = 400,
+ .read = read_hv_clock_msr,
+ .mask = CLOCKSOURCE_MASK(64),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+void __init hv_init_clocksource(void)
+{
+#ifdef CONFIG_HYPERV_TSCPAGE
+ if (ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE) {
+
+ u64 tsc_msr;
+ phys_addr_t phys_addr;
+
+ tsc_pg = vmalloc(PAGE_SIZE);
+ if (!tsc_pg)
+ goto register_msr_cs;
+
+ hyperv_cs = &hyperv_cs_tsc;
+ phys_addr = page_to_phys(vmalloc_to_page(tsc_pg));
+
+ /* The Hyper-V TLFS specifies to preserve the value of
+ * reserved bits in registers. So read the existing
+ * value, preserve the low order 12 bits, and add in
+ * the guest physical address (which already has at
+ * least the low 12 bits set to zero since it is page
+ * aligned). Also set the "enable" bit, which is bit 0.
+ */
+ hv_get_reference_tsc(tsc_msr);
+ tsc_msr &= GENMASK_ULL(11, 0);
+ tsc_msr = tsc_msr | 0x1 | (u64)phys_addr;
+ hv_set_reference_tsc(tsc_msr);
+
+ hv_set_clocksource_vdso(hyperv_cs_tsc);
+ clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100);
+
+ /*
+ * sched_clock_register is needed on ARM64 but
+ * is a no-op on x86
+ */
+ sched_clock_register(read_hv_sched_clock_tsc,
+ 64, HV_CLOCK_HZ);
+ return;
+ }
+register_msr_cs:
+#endif
+ /*
+ * For 32 bit guests just use the MSR based mechanism for reading
+ * the partition counter.
+ */
+ hyperv_cs = &hyperv_cs_msr;
+ if (ms_hyperv.features & HV_MSR_TIME_REF_COUNT_AVAILABLE) {
+ clocksource_register_hz(&hyperv_cs_msr, NSEC_PER_SEC/100);
+
+ /*
+ * sched_clock_register is needed on ARM64 but
+ * is a no-op on x86
+ */
+ sched_clock_register(read_hv_sched_clock_msr,
+ 64, HV_CLOCK_HZ);
+ }
+}
+EXPORT_SYMBOL_GPL(hv_init_clocksource);
diff --git a/include/clocksource/hyperv_timer.h b/include/clocksource/hyperv_timer.h
index ba5dc17..e17e8a2 100644
--- a/include/clocksource/hyperv_timer.h
+++ b/include/clocksource/hyperv_timer.h
@@ -13,6 +13,10 @@
#ifndef __CLKSOURCE_HYPERV_TIMER_H
#define __CLKSOURCE_HYPERV_TIMER_H
+#include <linux/clocksource.h>
+#include <linux/math64.h>
+#include <asm/mshyperv.h>
+
#define HV_MAX_MAX_DELTA_TICKS 0xffffffff
#define HV_MIN_DELTA_TICKS 1
@@ -24,4 +28,78 @@
extern void hv_stimer_global_cleanup(void);
extern void hv_stimer0_isr(void);
+#if IS_ENABLED(CONFIG_HYPERV)
+extern struct clocksource *hyperv_cs;
+extern void hv_init_clocksource(void);
+#endif /* CONFIG_HYPERV */
+
+#ifdef CONFIG_HYPERV_TSCPAGE
+extern struct ms_hyperv_tsc_page *hv_get_tsc_page(void);
+static inline u64 hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg,
+ u64 *cur_tsc)
+{
+ u64 scale, offset;
+ u32 sequence;
+
+ /*
+ * The protocol for reading Hyper-V TSC page is specified in Hypervisor
+ * Top-Level Functional Specification ver. 3.0 and above. To get the
+ * reference time we must do the following:
+ * - READ ReferenceTscSequence
+ * A special '0' value indicates the time source is unreliable and we
+ * need to use something else. The currently published specification
+ * versions (up to 4.0b) contain a mistake and wrongly claim '-1'
+ * instead of '0' as the special value, see commit c35b82ef0294.
+ * - ReferenceTime =
+ * ((RDTSC() * ReferenceTscScale) >> 64) + ReferenceTscOffset
+ * - READ ReferenceTscSequence again. In case its value has changed
+ * since our first reading we need to discard ReferenceTime and repeat
+ * the whole sequence as the hypervisor was updating the page in
+ * between.
+ */
+ do {
+ sequence = READ_ONCE(tsc_pg->tsc_sequence);
+ if (!sequence)
+ return U64_MAX;
+ /*
+ * Make sure we read sequence before we read other values from
+ * TSC page.
+ */
+ smp_rmb();
+
+ scale = READ_ONCE(tsc_pg->tsc_scale);
+ offset = READ_ONCE(tsc_pg->tsc_offset);
+ *cur_tsc = hv_get_raw_timer();
+
+ /*
+ * Make sure we read sequence after we read all other values
+ * from TSC page.
+ */
+ smp_rmb();
+
+ } while (READ_ONCE(tsc_pg->tsc_sequence) != sequence);
+
+ return mul_u64_u64_shr(*cur_tsc, scale, 64) + offset;
+}
+
+static inline u64 hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg)
+{
+ u64 cur_tsc;
+
+ return hv_read_tsc_page_tsc(tsc_pg, &cur_tsc);
+}
+
+#else /* CONFIG_HYPERV_TSC_PAGE */
+static inline struct ms_hyperv_tsc_page *hv_get_tsc_page(void)
+{
+ return NULL;
+}
+
+static inline u64 hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg,
+ u64 *cur_tsc)
+{
+ return U64_MAX;
+}
+#endif /* CONFIG_HYPERV_TSCPAGE */
+
#endif
--
1.8.3.1
^ permalink raw reply related
* RE: [PATCH v6 18/19] x86: Add support for generic vDSO
From: Michael Kelley @ 2019-06-28 18:40 UTC (permalink / raw)
To: Thomas Gleixner
Cc: Sasha Levin, Vincenzo Frascino, linux-arch@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org,
linux-kselftest@vger.kernel.org, Catalin Marinas, Will Deacon,
Arnd Bergmann, Russell King, Ralf Baechle, Paul Burton,
Daniel Lezcano, Mark Salyzyn, Peter Collingbourne, Shuah Khan,
Dmitry Safonov, Rasmus Villemoes, Huw Davies,
linux-hyperv@vger.kernel.org, Greg KH, Stephen Rothwell
In-Reply-To: <alpine.DEB.2.21.1906240221550.32342@nanos.tec.linutronix.de>
From: Thomas Gleixner <tglx@linutronix.de> Sent: Sunday, June 23, 2019 5:25 PM
>
> I don't care whether this goes into 5.3 or later. If you can provide me
> rebased self contained patches on top of
>
> git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers/vdso
>
> I'm happy to pull them in on top.
>
I've sent out "v4" of the patch set to create a Hyper-V clocksource, based
on the above tree. It is contained to Hyper-V code, plus updating a #include
statement in two of the VDSO files and in one KVM file. If the KVM file
update is problematic, the patch set can just wait until 5.3-rc1.
Michael
^ permalink raw reply
* Re: [PATCH v3 2/5] x86: hv: hv_init.c: Add functions to allocate/deallocate page for Hyper-V
From: Maya Nakamura @ 2019-06-29 6:50 UTC (permalink / raw)
To: Thomas Gleixner
Cc: mikelley, kys, haiyangz, sthemmin, sashal, x86, linux-hyperv,
linux-kernel
In-Reply-To: <alpine.DEB.2.21.1906272334560.32342@nanos.tec.linutronix.de>
On Thu, Jun 27, 2019 at 11:38:14PM +0200, Thomas Gleixner wrote:
> Maya,
>
> On Tue, 18 Jun 2019, Maya Nakamura wrote:
>
> > diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
> > index 0e033ef11a9f..e8960a83add7 100644
> > --- a/arch/x86/hyperv/hv_init.c
> > +++ b/arch/x86/hyperv/hv_init.c
> > @@ -37,6 +37,20 @@ EXPORT_SYMBOL_GPL(hyperv_pcpu_input_arg);
> > u32 hv_max_vp_index;
> > EXPORT_SYMBOL_GPL(hv_max_vp_index);
> >
> > +void *hv_alloc_hyperv_page(void)
> > +{
> > + BUILD_BUG_ON(PAGE_SIZE != HV_HYP_PAGE_SIZE);
> > +
> > + return (void *)__get_free_page(GFP_KERNEL);
> > +}
> > +EXPORT_SYMBOL_GPL(hv_alloc_hyperv_page);
> > +
> > +void hv_free_hyperv_page(unsigned long addr)
> > +{
> > + free_page(addr);
> > +}
> > +EXPORT_SYMBOL_GPL(hv_free_hyperv_page);
>
> These functions need to be declared in a header file.
>
> Thanks,
>
> tglx
>
Thank you for pointing that out, Thomas. I will resubmit my patch set to
include a header file with the function prototypes.
^ permalink raw reply
* [PATCH v5 1/2] clocksource/drivers: Make Hyper-V clocksource ISA agnostic
From: Michael Kelley @ 2019-07-01 4:25 UTC (permalink / raw)
To: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
x86@kernel.org
Cc: Michael Kelley, will.deacon@arm.com, catalin.marinas@arm.com,
mark.rutland@arm.com, linux-arm-kernel@lists.infradead.org,
gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
linux-hyperv@vger.kernel.org, olaf@aepfle.de, apw@canonical.com,
vkuznets, jasowang@redhat.com, marcelo.cerri@canonical.com,
Sunil Muthuswamy, KY Srinivasan, sashal@kernel.org,
vincenzo.frascino@arm.com, linux-arch@vger.kernel.org,
linux-mips@vger.kernel.org, linux-kselftest@vger.kernel.org,
arnd@arndb.de, linux@armlinux.org.uk, ralf@linux-mips.org,
paul.burton@mips.com, daniel.lezcano@linaro.org,
salyzyn@android.com, pcc@google.com, shuah@kernel.org,
0x7f454c46@gmail.com, linux@rasmusvillemoes.dk,
huw@codeweavers.com, sfr@canb.auug.org.au, pbonzini@redhat.com,
rkrcmar@redhat.com, kvm@vger.kernel.org
In-Reply-To: <1561955054-1838-1-git-send-email-mikelley@microsoft.com>
Hyper-V clock/timer code and data structures are currently mixed
in with other code in the ISA independent drivers/hv directory as
well as the ISA dependent Hyper-V code under arch/x86. Consolidate
this code and data structures into a Hyper-V clocksource driver to
better follow the Linux model. In doing so, separate out the ISA
dependent portions so the new clocksource driver works for x86 and
for the in-process Hyper-V on ARM64 code.
To start, move the existing clockevents code to create the
new clocksource driver. Update the VMbus driver to call
initialization and cleanup routines since the Hyper-V
synthetic timers are not independently enumerated in ACPI.
No behavior is changed and no new functionality is added.
Suggested-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
---
MAINTAINERS | 2 +
arch/x86/include/asm/hyperv-tlfs.h | 6 ++
arch/x86/kernel/cpu/mshyperv.c | 4 +-
drivers/clocksource/Makefile | 1 +
drivers/clocksource/hyperv_timer.c | 200 +++++++++++++++++++++++++++++++++++++
drivers/hv/Kconfig | 3 +
drivers/hv/hv.c | 156 +----------------------------
drivers/hv/hyperv_vmbus.h | 3 -
drivers/hv/vmbus_drv.c | 42 ++++----
include/clocksource/hyperv_timer.h | 27 +++++
10 files changed, 268 insertions(+), 176 deletions(-)
create mode 100644 drivers/clocksource/hyperv_timer.c
create mode 100644 include/clocksource/hyperv_timer.h
diff --git a/MAINTAINERS b/MAINTAINERS
index a281297..bfde42a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7313,6 +7313,7 @@ F: arch/x86/include/asm/trace/hyperv.h
F: arch/x86/include/asm/hyperv-tlfs.h
F: arch/x86/kernel/cpu/mshyperv.c
F: arch/x86/hyperv
+F: drivers/clocksource/hyperv_timer.c
F: drivers/hid/hid-hyperv.c
F: drivers/hv/
F: drivers/input/serio/hyperv-keyboard.c
@@ -7323,6 +7324,7 @@ F: drivers/uio/uio_hv_generic.c
F: drivers/video/fbdev/hyperv_fb.c
F: drivers/iommu/hyperv_iommu.c
F: net/vmw_vsock/hyperv_transport.c
+F: include/clocksource/hyperv_timer.h
F: include/linux/hyperv.h
F: include/uapi/linux/hyperv.h
F: tools/hv/
diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index cdf44aa..af78cd7 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/arch/x86/include/asm/hyperv-tlfs.h
@@ -401,6 +401,12 @@ enum HV_GENERIC_SET_FORMAT {
#define HV_STATUS_INVALID_CONNECTION_ID 18
#define HV_STATUS_INSUFFICIENT_BUFFERS 19
+/*
+ * The Hyper-V TimeRefCount register and the TSC
+ * page provide a guest VM clock with 100ns tick rate
+ */
+#define HV_CLOCK_HZ (NSEC_PER_SEC/100)
+
typedef struct _HV_REFERENCE_TSC_PAGE {
__u32 tsc_sequence;
__u32 res1;
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 7df29f0..1e5f7a0 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -17,6 +17,7 @@
#include <linux/irq.h>
#include <linux/kexec.h>
#include <linux/i8253.h>
+#include <linux/random.h>
#include <asm/processor.h>
#include <asm/hypervisor.h>
#include <asm/hyperv-tlfs.h>
@@ -80,6 +81,7 @@ __visible void __irq_entry hv_stimer0_vector_handler(struct pt_regs *regs)
inc_irq_stat(hyperv_stimer0_count);
if (hv_stimer0_handler)
hv_stimer0_handler();
+ add_interrupt_randomness(HYPERV_STIMER0_VECTOR, 0);
ack_APIC_irq();
exiting_irq();
@@ -89,7 +91,7 @@ __visible void __irq_entry hv_stimer0_vector_handler(struct pt_regs *regs)
int hv_setup_stimer0_irq(int *irq, int *vector, void (*handler)(void))
{
*vector = HYPERV_STIMER0_VECTOR;
- *irq = 0; /* Unused on x86/x64 */
+ *irq = -1; /* Unused on x86/x64 */
hv_stimer0_handler = handler;
return 0;
}
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 236858f..2b65c5f 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -84,3 +84,4 @@ obj-$(CONFIG_ATCPIT100_TIMER) += timer-atcpit100.o
obj-$(CONFIG_RISCV_TIMER) += timer-riscv.o
obj-$(CONFIG_CSKY_MP_TIMER) += timer-mp-csky.o
obj-$(CONFIG_GX6605S_TIMER) += timer-gx6605s.o
+obj-$(CONFIG_HYPERV_TIMER) += hyperv_timer.o
diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c
new file mode 100644
index 0000000..68a28af
--- /dev/null
+++ b/drivers/clocksource/hyperv_timer.c
@@ -0,0 +1,200 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Clocksource driver for the synthetic counter and timers
+ * provided by the Hyper-V hypervisor to guest VMs, as described
+ * in the Hyper-V Top Level Functional Spec (TLFS). This driver
+ * is instruction set architecture independent.
+ *
+ * Copyright (C) 2019, Microsoft, Inc.
+ *
+ * Author: Michael Kelley <mikelley@microsoft.com>
+ */
+
+#include <linux/percpu.h>
+#include <linux/cpumask.h>
+#include <linux/clockchips.h>
+#include <linux/mm.h>
+#include <clocksource/hyperv_timer.h>
+#include <asm/hyperv-tlfs.h>
+#include <asm/mshyperv.h>
+
+static struct clock_event_device __percpu *hv_clock_event;
+
+/*
+ * If false, we're using the old mechanism for stimer0 interrupts
+ * where it sends a VMbus message when it expires. The old
+ * mechanism is used when running on older versions of Hyper-V
+ * that don't support Direct Mode. While Hyper-V provides
+ * four stimer's per CPU, Linux uses only stimer0.
+ */
+static bool direct_mode_enabled;
+
+static int stimer0_irq;
+static int stimer0_vector;
+static int stimer0_message_sint;
+
+/*
+ * ISR for when stimer0 is operating in Direct Mode. Direct Mode
+ * does not use VMbus or any VMbus messages, so process here and not
+ * in the VMbus driver code.
+ */
+void hv_stimer0_isr(void)
+{
+ struct clock_event_device *ce;
+
+ ce = this_cpu_ptr(hv_clock_event);
+ ce->event_handler(ce);
+}
+EXPORT_SYMBOL_GPL(hv_stimer0_isr);
+
+static int hv_ce_set_next_event(unsigned long delta,
+ struct clock_event_device *evt)
+{
+ u64 current_tick;
+
+ current_tick = hyperv_cs->read(NULL);
+ current_tick += delta;
+ hv_init_timer(0, current_tick);
+ return 0;
+}
+
+static int hv_ce_shutdown(struct clock_event_device *evt)
+{
+ hv_init_timer(0, 0);
+ hv_init_timer_config(0, 0);
+ if (direct_mode_enabled)
+ hv_disable_stimer0_percpu_irq(stimer0_irq);
+
+ return 0;
+}
+
+static int hv_ce_set_oneshot(struct clock_event_device *evt)
+{
+ union hv_stimer_config timer_cfg;
+
+ timer_cfg.as_uint64 = 0;
+ timer_cfg.enable = 1;
+ timer_cfg.auto_enable = 1;
+ if (direct_mode_enabled) {
+ /*
+ * When it expires, the timer will directly interrupt
+ * on the specified hardware vector/IRQ.
+ */
+ timer_cfg.direct_mode = 1;
+ timer_cfg.apic_vector = stimer0_vector;
+ hv_enable_stimer0_percpu_irq(stimer0_irq);
+ } else {
+ /*
+ * When it expires, the timer will generate a VMbus message,
+ * to be handled by the normal VMbus interrupt handler.
+ */
+ timer_cfg.direct_mode = 0;
+ timer_cfg.sintx = stimer0_message_sint;
+ }
+ hv_init_timer_config(0, timer_cfg.as_uint64);
+ return 0;
+}
+
+/*
+ * hv_stimer_init - Per-cpu initialization of the clockevent
+ */
+void hv_stimer_init(unsigned int cpu)
+{
+ struct clock_event_device *ce;
+
+ /*
+ * Synthetic timers are always available except on old versions of
+ * Hyper-V on x86. In that case, just return as Linux will use a
+ * clocksource based on emulated PIT or LAPIC timer hardware.
+ */
+ if (!(ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE))
+ return;
+
+ ce = per_cpu_ptr(hv_clock_event, cpu);
+ ce->name = "Hyper-V clockevent";
+ ce->features = CLOCK_EVT_FEAT_ONESHOT;
+ ce->cpumask = cpumask_of(cpu);
+ ce->rating = 1000;
+ ce->set_state_shutdown = hv_ce_shutdown;
+ ce->set_state_oneshot = hv_ce_set_oneshot;
+ ce->set_next_event = hv_ce_set_next_event;
+
+ clockevents_config_and_register(ce,
+ HV_CLOCK_HZ,
+ HV_MIN_DELTA_TICKS,
+ HV_MAX_MAX_DELTA_TICKS);
+}
+EXPORT_SYMBOL_GPL(hv_stimer_init);
+
+/*
+ * hv_stimer_cleanup - Per-cpu cleanup of the clockevent
+ */
+void hv_stimer_cleanup(unsigned int cpu)
+{
+ struct clock_event_device *ce;
+
+ /* Turn off clockevent device */
+ if (ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE) {
+ ce = per_cpu_ptr(hv_clock_event, cpu);
+ hv_ce_shutdown(ce);
+ }
+}
+EXPORT_SYMBOL_GPL(hv_stimer_cleanup);
+
+/* hv_stimer_alloc - Global initialization of the clockevent and stimer0 */
+int hv_stimer_alloc(int sint)
+{
+ int ret;
+
+ hv_clock_event = alloc_percpu(struct clock_event_device);
+ if (!hv_clock_event)
+ return -ENOMEM;
+
+ direct_mode_enabled = ms_hyperv.misc_features &
+ HV_STIMER_DIRECT_MODE_AVAILABLE;
+ if (direct_mode_enabled) {
+ ret = hv_setup_stimer0_irq(&stimer0_irq, &stimer0_vector,
+ hv_stimer0_isr);
+ if (ret) {
+ free_percpu(hv_clock_event);
+ hv_clock_event = NULL;
+ return ret;
+ }
+ }
+
+ stimer0_message_sint = sint;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(hv_stimer_alloc);
+
+/* hv_stimer_free - Free global resources allocated by hv_stimer_alloc() */
+void hv_stimer_free(void)
+{
+ if (direct_mode_enabled && (stimer0_irq != 0)) {
+ hv_remove_stimer0_irq(stimer0_irq);
+ stimer0_irq = 0;
+ }
+ free_percpu(hv_clock_event);
+ hv_clock_event = NULL;
+}
+EXPORT_SYMBOL_GPL(hv_stimer_free);
+
+/*
+ * Do a global cleanup of clockevents for the cases of kexec and
+ * vmbus exit
+ */
+void hv_stimer_global_cleanup(void)
+{
+ int cpu;
+ struct clock_event_device *ce;
+
+ if (ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE) {
+ for_each_present_cpu(cpu) {
+ ce = per_cpu_ptr(hv_clock_event, cpu);
+ clockevents_unbind_device(ce, cpu);
+ }
+ }
+ hv_stimer_free();
+}
+EXPORT_SYMBOL_GPL(hv_stimer_global_cleanup);
diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig
index 1c1a251..c423e57 100644
--- a/drivers/hv/Kconfig
+++ b/drivers/hv/Kconfig
@@ -10,6 +10,9 @@ config HYPERV
Select this option to run Linux as a Hyper-V client operating
system.
+config HYPERV_TIMER
+ def_bool HYPERV
+
config HYPERV_TSCPAGE
def_bool HYPERV && X86_64
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index a1ea482..6188fb7 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -16,6 +16,7 @@
#include <linux/version.h>
#include <linux/random.h>
#include <linux/clockchips.h>
+#include <clocksource/hyperv_timer.h>
#include <asm/mshyperv.h>
#include "hyperv_vmbus.h"
@@ -23,21 +24,6 @@
struct hv_context hv_context;
/*
- * If false, we're using the old mechanism for stimer0 interrupts
- * where it sends a VMbus message when it expires. The old
- * mechanism is used when running on older versions of Hyper-V
- * that don't support Direct Mode. While Hyper-V provides
- * four stimer's per CPU, Linux uses only stimer0.
- */
-static bool direct_mode_enabled;
-static int stimer0_irq;
-static int stimer0_vector;
-
-#define HV_TIMER_FREQUENCY (10 * 1000 * 1000) /* 100ns period */
-#define HV_MAX_MAX_DELTA_TICKS 0xffffffff
-#define HV_MIN_DELTA_TICKS 1
-
-/*
* hv_init - Main initialization routine.
*
* This routine must be called before any other routines in here are called
@@ -47,9 +33,6 @@ int hv_init(void)
hv_context.cpu_context = alloc_percpu(struct hv_per_cpu_context);
if (!hv_context.cpu_context)
return -ENOMEM;
-
- direct_mode_enabled = ms_hyperv.misc_features &
- HV_STIMER_DIRECT_MODE_AVAILABLE;
return 0;
}
@@ -88,89 +71,6 @@ int hv_post_message(union hv_connection_id connection_id,
return status & 0xFFFF;
}
-/*
- * ISR for when stimer0 is operating in Direct Mode. Direct Mode
- * does not use VMbus or any VMbus messages, so process here and not
- * in the VMbus driver code.
- */
-
-static void hv_stimer0_isr(void)
-{
- struct hv_per_cpu_context *hv_cpu;
-
- hv_cpu = this_cpu_ptr(hv_context.cpu_context);
- hv_cpu->clk_evt->event_handler(hv_cpu->clk_evt);
- add_interrupt_randomness(stimer0_vector, 0);
-}
-
-static int hv_ce_set_next_event(unsigned long delta,
- struct clock_event_device *evt)
-{
- u64 current_tick;
-
- WARN_ON(!clockevent_state_oneshot(evt));
-
- current_tick = hyperv_cs->read(NULL);
- current_tick += delta;
- hv_init_timer(0, current_tick);
- return 0;
-}
-
-static int hv_ce_shutdown(struct clock_event_device *evt)
-{
- hv_init_timer(0, 0);
- hv_init_timer_config(0, 0);
- if (direct_mode_enabled)
- hv_disable_stimer0_percpu_irq(stimer0_irq);
-
- return 0;
-}
-
-static int hv_ce_set_oneshot(struct clock_event_device *evt)
-{
- union hv_stimer_config timer_cfg;
-
- timer_cfg.as_uint64 = 0;
- timer_cfg.enable = 1;
- timer_cfg.auto_enable = 1;
- if (direct_mode_enabled) {
- /*
- * When it expires, the timer will directly interrupt
- * on the specified hardware vector/IRQ.
- */
- timer_cfg.direct_mode = 1;
- timer_cfg.apic_vector = stimer0_vector;
- hv_enable_stimer0_percpu_irq(stimer0_irq);
- } else {
- /*
- * When it expires, the timer will generate a VMbus message,
- * to be handled by the normal VMbus interrupt handler.
- */
- timer_cfg.direct_mode = 0;
- timer_cfg.sintx = VMBUS_MESSAGE_SINT;
- }
- hv_init_timer_config(0, timer_cfg.as_uint64);
- return 0;
-}
-
-static void hv_init_clockevent_device(struct clock_event_device *dev, int cpu)
-{
- dev->name = "Hyper-V clockevent";
- dev->features = CLOCK_EVT_FEAT_ONESHOT;
- dev->cpumask = cpumask_of(cpu);
- dev->rating = 1000;
- /*
- * Avoid settint dev->owner = THIS_MODULE deliberately as doing so will
- * result in clockevents_config_and_register() taking additional
- * references to the hv_vmbus module making it impossible to unload.
- */
-
- dev->set_state_shutdown = hv_ce_shutdown;
- dev->set_state_oneshot = hv_ce_set_oneshot;
- dev->set_next_event = hv_ce_set_next_event;
-}
-
-
int hv_synic_alloc(void)
{
int cpu;
@@ -199,14 +99,6 @@ int hv_synic_alloc(void)
tasklet_init(&hv_cpu->msg_dpc,
vmbus_on_msg_dpc, (unsigned long) hv_cpu);
- hv_cpu->clk_evt = kzalloc(sizeof(struct clock_event_device),
- GFP_KERNEL);
- if (hv_cpu->clk_evt == NULL) {
- pr_err("Unable to allocate clock event device\n");
- goto err;
- }
- hv_init_clockevent_device(hv_cpu->clk_evt, cpu);
-
hv_cpu->synic_message_page =
(void *)get_zeroed_page(GFP_ATOMIC);
if (hv_cpu->synic_message_page == NULL) {
@@ -229,11 +121,6 @@ int hv_synic_alloc(void)
INIT_LIST_HEAD(&hv_cpu->chan_list);
}
- if (direct_mode_enabled &&
- hv_setup_stimer0_irq(&stimer0_irq, &stimer0_vector,
- hv_stimer0_isr))
- goto err;
-
return 0;
err:
/*
@@ -252,7 +139,6 @@ void hv_synic_free(void)
struct hv_per_cpu_context *hv_cpu
= per_cpu_ptr(hv_context.cpu_context, cpu);
- kfree(hv_cpu->clk_evt);
free_page((unsigned long)hv_cpu->synic_event_page);
free_page((unsigned long)hv_cpu->synic_message_page);
free_page((unsigned long)hv_cpu->post_msg_page);
@@ -311,36 +197,9 @@ int hv_synic_init(unsigned int cpu)
hv_set_synic_state(sctrl.as_uint64);
- /*
- * Register the per-cpu clockevent source.
- */
- if (ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE)
- clockevents_config_and_register(hv_cpu->clk_evt,
- HV_TIMER_FREQUENCY,
- HV_MIN_DELTA_TICKS,
- HV_MAX_MAX_DELTA_TICKS);
- return 0;
-}
-
-/*
- * hv_synic_clockevents_cleanup - Cleanup clockevent devices
- */
-void hv_synic_clockevents_cleanup(void)
-{
- int cpu;
+ hv_stimer_init(cpu);
- if (!(ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE))
- return;
-
- if (direct_mode_enabled)
- hv_remove_stimer0_irq(stimer0_irq);
-
- for_each_present_cpu(cpu) {
- struct hv_per_cpu_context *hv_cpu
- = per_cpu_ptr(hv_context.cpu_context, cpu);
-
- clockevents_unbind_device(hv_cpu->clk_evt, cpu);
- }
+ return 0;
}
/*
@@ -388,14 +247,7 @@ int hv_synic_cleanup(unsigned int cpu)
if (channel_found && vmbus_connection.conn_state == CONNECTED)
return -EBUSY;
- /* Turn off clockevent device */
- if (ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE) {
- struct hv_per_cpu_context *hv_cpu
- = this_cpu_ptr(hv_context.cpu_context);
-
- clockevents_unbind_device(hv_cpu->clk_evt, cpu);
- hv_ce_shutdown(hv_cpu->clk_evt);
- }
+ hv_stimer_cleanup(cpu);
hv_get_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index b8e1ff0..362e70e 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -138,7 +138,6 @@ struct hv_per_cpu_context {
* per-cpu list of the channels based on their CPU affinity.
*/
struct list_head chan_list;
- struct clock_event_device *clk_evt;
};
struct hv_context {
@@ -176,8 +175,6 @@ extern int hv_post_message(union hv_connection_id connection_id,
extern int hv_synic_cleanup(unsigned int cpu);
-extern void hv_synic_clockevents_cleanup(void);
-
/* Interface */
void hv_ringbuffer_pre_init(struct vmbus_channel *channel);
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 92b1874..72d5a7c 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -30,6 +30,7 @@
#include <linux/kdebug.h>
#include <linux/efi.h>
#include <linux/random.h>
+#include <clocksource/hyperv_timer.h>
#include "hyperv_vmbus.h"
struct vmbus_dynid {
@@ -955,17 +956,6 @@ static void vmbus_onmessage_work(struct work_struct *work)
kfree(ctx);
}
-static void hv_process_timer_expiration(struct hv_message *msg,
- struct hv_per_cpu_context *hv_cpu)
-{
- struct clock_event_device *dev = hv_cpu->clk_evt;
-
- if (dev->event_handler)
- dev->event_handler(dev);
-
- vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
-}
-
void vmbus_on_msg_dpc(unsigned long data)
{
struct hv_per_cpu_context *hv_cpu = (void *)data;
@@ -1159,9 +1149,10 @@ static void vmbus_isr(void)
/* Check if there are actual msgs to be processed */
if (msg->header.message_type != HVMSG_NONE) {
- if (msg->header.message_type == HVMSG_TIMER_EXPIRED)
- hv_process_timer_expiration(msg, hv_cpu);
- else
+ if (msg->header.message_type == HVMSG_TIMER_EXPIRED) {
+ hv_stimer0_isr();
+ vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
+ } else
tasklet_schedule(&hv_cpu->msg_dpc);
}
@@ -1263,14 +1254,19 @@ static int vmbus_bus_init(void)
ret = hv_synic_alloc();
if (ret)
goto err_alloc;
+
+ ret = hv_stimer_alloc(VMBUS_MESSAGE_SINT);
+ if (ret < 0)
+ goto err_alloc;
+
/*
- * Initialize the per-cpu interrupt state and
- * connect to the host.
+ * Initialize the per-cpu interrupt state and stimer state.
+ * Then connect to the host.
*/
ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hyperv/vmbus:online",
hv_synic_init, hv_synic_cleanup);
if (ret < 0)
- goto err_alloc;
+ goto err_cpuhp;
hyperv_cpuhp_online = ret;
ret = vmbus_connect();
@@ -1318,6 +1314,8 @@ static int vmbus_bus_init(void)
err_connect:
cpuhp_remove_state(hyperv_cpuhp_online);
+err_cpuhp:
+ hv_stimer_free();
err_alloc:
hv_synic_free();
hv_remove_vmbus_irq();
@@ -2064,7 +2062,7 @@ static int vmbus_acpi_add(struct acpi_device *device)
static void hv_kexec_handler(void)
{
- hv_synic_clockevents_cleanup();
+ hv_stimer_global_cleanup();
vmbus_initiate_unload(false);
vmbus_connection.conn_state = DISCONNECTED;
/* Make sure conn_state is set as hv_synic_cleanup checks for it */
@@ -2075,6 +2073,8 @@ static void hv_kexec_handler(void)
static void hv_crash_handler(struct pt_regs *regs)
{
+ int cpu;
+
vmbus_initiate_unload(true);
/*
* In crash handler we can't schedule synic cleanup for all CPUs,
@@ -2082,7 +2082,9 @@ static void hv_crash_handler(struct pt_regs *regs)
* for kdump.
*/
vmbus_connection.conn_state = DISCONNECTED;
- hv_synic_cleanup(smp_processor_id());
+ cpu = smp_processor_id();
+ hv_stimer_cleanup(cpu);
+ hv_synic_cleanup(cpu);
hyperv_cleanup();
};
@@ -2131,7 +2133,7 @@ static void __exit vmbus_exit(void)
hv_remove_kexec_handler();
hv_remove_crash_handler();
vmbus_connection.conn_state = DISCONNECTED;
- hv_synic_clockevents_cleanup();
+ hv_stimer_global_cleanup();
vmbus_disconnect();
hv_remove_vmbus_irq();
for_each_online_cpu(cpu) {
diff --git a/include/clocksource/hyperv_timer.h b/include/clocksource/hyperv_timer.h
new file mode 100644
index 0000000..0cd73f7
--- /dev/null
+++ b/include/clocksource/hyperv_timer.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Definitions for the clocksource provided by the Hyper-V
+ * hypervisor to guest VMs, as described in the Hyper-V Top
+ * Level Functional Spec (TLFS).
+ *
+ * Copyright (C) 2019, Microsoft, Inc.
+ *
+ * Author: Michael Kelley <mikelley@microsoft.com>
+ */
+
+#ifndef __CLKSOURCE_HYPERV_TIMER_H
+#define __CLKSOURCE_HYPERV_TIMER_H
+
+#define HV_MAX_MAX_DELTA_TICKS 0xffffffff
+#define HV_MIN_DELTA_TICKS 1
+
+/* Routines called by the VMbus driver */
+extern int hv_stimer_alloc(int sint);
+extern void hv_stimer_free(void);
+extern void hv_stimer_init(unsigned int cpu);
+extern void hv_stimer_cleanup(unsigned int cpu);
+extern void hv_stimer_global_cleanup(void);
+extern void hv_stimer0_isr(void);
+
+#endif
--
1.8.3.1
^ permalink raw reply related
* [PATCH v5 2/2] clocksource/drivers: Continue making Hyper-V clocksource ISA agnostic
From: Michael Kelley @ 2019-07-01 4:26 UTC (permalink / raw)
To: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
x86@kernel.org
Cc: Michael Kelley, will.deacon@arm.com, catalin.marinas@arm.com,
mark.rutland@arm.com, linux-arm-kernel@lists.infradead.org,
gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
linux-hyperv@vger.kernel.org, olaf@aepfle.de, apw@canonical.com,
vkuznets, jasowang@redhat.com, marcelo.cerri@canonical.com,
Sunil Muthuswamy, KY Srinivasan, sashal@kernel.org,
vincenzo.frascino@arm.com, linux-arch@vger.kernel.org,
linux-mips@vger.kernel.org, linux-kselftest@vger.kernel.org,
arnd@arndb.de, linux@armlinux.org.uk, ralf@linux-mips.org,
paul.burton@mips.com, daniel.lezcano@linaro.org,
salyzyn@android.com, pcc@google.com, shuah@kernel.org,
0x7f454c46@gmail.com, linux@rasmusvillemoes.dk,
huw@codeweavers.com, sfr@canb.auug.org.au, pbonzini@redhat.com,
rkrcmar@redhat.com, kvm@vger.kernel.org
In-Reply-To: <1561955054-1838-1-git-send-email-mikelley@microsoft.com>
Continue consolidating Hyper-V clock and timer code into an ISA
independent Hyper-V clocksource driver. Move the existing clocksource
code under drivers/hv and arch/x86 to the new clocksource driver
while separating out the ISA dependencies. Update Hyper-V
initialization to call initialization and cleanup routines since the
Hyper-V synthetic clock is not independently enumerated in ACPI.
Update Hyper-V clocksource users in KVM and VDSO to get definitions
from a new include file.
No behavior is changed and no new functionality is added.
Suggested-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
---
arch/x86/entry/vdso/vma.c | 2 +-
arch/x86/hyperv/hv_init.c | 91 +-------------------
arch/x86/include/asm/mshyperv.h | 81 +++---------------
arch/x86/include/asm/vdso/gettimeofday.h | 2 +-
arch/x86/kvm/x86.c | 1 +
drivers/clocksource/hyperv_timer.c | 139 +++++++++++++++++++++++++++++++
drivers/hv/hv_util.c | 1 +
include/clocksource/hyperv_timer.h | 78 +++++++++++++++++
8 files changed, 235 insertions(+), 160 deletions(-)
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 8db1f59..349a61d 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -22,7 +22,7 @@
#include <asm/page.h>
#include <asm/desc.h>
#include <asm/cpufeature.h>
-#include <asm/mshyperv.h>
+#include <clocksource/hyperv_timer.h>
#if defined(CONFIG_X86_64)
unsigned int __read_mostly vdso64_enabled = 1;
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 1608050..0e033ef 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -17,64 +17,13 @@
#include <linux/version.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
-#include <linux/clockchips.h>
#include <linux/hyperv.h>
#include <linux/slab.h>
#include <linux/cpuhotplug.h>
-
-#ifdef CONFIG_HYPERV_TSCPAGE
-
-static struct ms_hyperv_tsc_page *tsc_pg;
-
-struct ms_hyperv_tsc_page *hv_get_tsc_page(void)
-{
- return tsc_pg;
-}
-EXPORT_SYMBOL_GPL(hv_get_tsc_page);
-
-static u64 read_hv_clock_tsc(struct clocksource *arg)
-{
- u64 current_tick = hv_read_tsc_page(tsc_pg);
-
- if (current_tick == U64_MAX)
- rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
-
- return current_tick;
-}
-
-static struct clocksource hyperv_cs_tsc = {
- .name = "hyperv_clocksource_tsc_page",
- .rating = 400,
- .read = read_hv_clock_tsc,
- .mask = CLOCKSOURCE_MASK(64),
- .flags = CLOCK_SOURCE_IS_CONTINUOUS,
-};
-#endif
-
-static u64 read_hv_clock_msr(struct clocksource *arg)
-{
- u64 current_tick;
- /*
- * Read the partition counter to get the current tick count. This count
- * is set to 0 when the partition is created and is incremented in
- * 100 nanosecond units.
- */
- rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
- return current_tick;
-}
-
-static struct clocksource hyperv_cs_msr = {
- .name = "hyperv_clocksource_msr",
- .rating = 400,
- .read = read_hv_clock_msr,
- .mask = CLOCKSOURCE_MASK(64),
- .flags = CLOCK_SOURCE_IS_CONTINUOUS,
-};
+#include <clocksource/hyperv_timer.h>
void *hv_hypercall_pg;
EXPORT_SYMBOL_GPL(hv_hypercall_pg);
-struct clocksource *hyperv_cs;
-EXPORT_SYMBOL_GPL(hyperv_cs);
u32 *hv_vp_index;
EXPORT_SYMBOL_GPL(hv_vp_index);
@@ -343,42 +292,8 @@ void __init hyperv_init(void)
x86_init.pci.arch_init = hv_pci_init;
- /*
- * Register Hyper-V specific clocksource.
- */
-#ifdef CONFIG_HYPERV_TSCPAGE
- if (ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE) {
- union hv_x64_msr_hypercall_contents tsc_msr;
-
- tsc_pg = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL);
- if (!tsc_pg)
- goto register_msr_cs;
-
- hyperv_cs = &hyperv_cs_tsc;
-
- rdmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
-
- tsc_msr.enable = 1;
- tsc_msr.guest_physical_address = vmalloc_to_pfn(tsc_pg);
-
- wrmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
-
- hyperv_cs_tsc.archdata.vclock_mode = VCLOCK_HVCLOCK;
-
- clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100);
- return;
- }
-register_msr_cs:
-#endif
- /*
- * For 32 bit guests just use the MSR based mechanism for reading
- * the partition counter.
- */
-
- hyperv_cs = &hyperv_cs_msr;
- if (ms_hyperv.features & HV_MSR_TIME_REF_COUNT_AVAILABLE)
- clocksource_register_hz(&hyperv_cs_msr, NSEC_PER_SEC/100);
-
+ /* Register Hyper-V specific clocksource */
+ hv_init_clocksource();
return;
remove_cpuhp_state:
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index cc60e61..f4fa8a9 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -105,6 +105,17 @@ static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
#define hv_get_crash_ctl(val) \
rdmsrl(HV_X64_MSR_CRASH_CTL, val)
+#define hv_get_time_ref_count(val) \
+ rdmsrl(HV_X64_MSR_TIME_REF_COUNT, val)
+
+#define hv_get_reference_tsc(val) \
+ rdmsrl(HV_X64_MSR_REFERENCE_TSC, val)
+#define hv_set_reference_tsc(val) \
+ wrmsrl(HV_X64_MSR_REFERENCE_TSC, val)
+#define hv_set_clocksource_vdso(val) \
+ ((val).archdata.vclock_mode = VCLOCK_HVCLOCK)
+#define hv_get_raw_timer() rdtsc_ordered()
+
void hyperv_callback_vector(void);
void hyperv_reenlightenment_vector(void);
#ifdef CONFIG_TRACING
@@ -133,7 +144,6 @@ static inline void hv_disable_stimer0_percpu_irq(int irq) {}
#if IS_ENABLED(CONFIG_HYPERV)
-extern struct clocksource *hyperv_cs;
extern void *hv_hypercall_pg;
extern void __percpu **hyperv_pcpu_input_arg;
@@ -387,73 +397,4 @@ static inline int hyperv_flush_guest_mapping_range(u64 as,
}
#endif /* CONFIG_HYPERV */
-#ifdef CONFIG_HYPERV_TSCPAGE
-struct ms_hyperv_tsc_page *hv_get_tsc_page(void);
-static inline u64 hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg,
- u64 *cur_tsc)
-{
- u64 scale, offset;
- u32 sequence;
-
- /*
- * The protocol for reading Hyper-V TSC page is specified in Hypervisor
- * Top-Level Functional Specification ver. 3.0 and above. To get the
- * reference time we must do the following:
- * - READ ReferenceTscSequence
- * A special '0' value indicates the time source is unreliable and we
- * need to use something else. The currently published specification
- * versions (up to 4.0b) contain a mistake and wrongly claim '-1'
- * instead of '0' as the special value, see commit c35b82ef0294.
- * - ReferenceTime =
- * ((RDTSC() * ReferenceTscScale) >> 64) + ReferenceTscOffset
- * - READ ReferenceTscSequence again. In case its value has changed
- * since our first reading we need to discard ReferenceTime and repeat
- * the whole sequence as the hypervisor was updating the page in
- * between.
- */
- do {
- sequence = READ_ONCE(tsc_pg->tsc_sequence);
- if (!sequence)
- return U64_MAX;
- /*
- * Make sure we read sequence before we read other values from
- * TSC page.
- */
- smp_rmb();
-
- scale = READ_ONCE(tsc_pg->tsc_scale);
- offset = READ_ONCE(tsc_pg->tsc_offset);
- *cur_tsc = rdtsc_ordered();
-
- /*
- * Make sure we read sequence after we read all other values
- * from TSC page.
- */
- smp_rmb();
-
- } while (READ_ONCE(tsc_pg->tsc_sequence) != sequence);
-
- return mul_u64_u64_shr(*cur_tsc, scale, 64) + offset;
-}
-
-static inline u64 hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg)
-{
- u64 cur_tsc;
-
- return hv_read_tsc_page_tsc(tsc_pg, &cur_tsc);
-}
-
-#else
-static inline struct ms_hyperv_tsc_page *hv_get_tsc_page(void)
-{
- return NULL;
-}
-
-static inline u64 hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg,
- u64 *cur_tsc)
-{
- BUG();
- return U64_MAX;
-}
-#endif
#endif
diff --git a/arch/x86/include/asm/vdso/gettimeofday.h b/arch/x86/include/asm/vdso/gettimeofday.h
index a14039a..ae91429 100644
--- a/arch/x86/include/asm/vdso/gettimeofday.h
+++ b/arch/x86/include/asm/vdso/gettimeofday.h
@@ -18,7 +18,7 @@
#include <asm/unistd.h>
#include <asm/msr.h>
#include <asm/pvclock.h>
-#include <asm/mshyperv.h>
+#include <clocksource/hyperv_timer.h>
#define __vdso_data (VVAR(_vdso_data))
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9857992..07ddb1e 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -67,6 +67,7 @@
#include <asm/mshyperv.h>
#include <asm/hypervisor.h>
#include <asm/intel_pt.h>
+#include <clocksource/hyperv_timer.h>
#define CREATE_TRACE_POINTS
#include "trace.h"
diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c
index 68a28af..ba2c79e 100644
--- a/drivers/clocksource/hyperv_timer.c
+++ b/drivers/clocksource/hyperv_timer.c
@@ -14,6 +14,8 @@
#include <linux/percpu.h>
#include <linux/cpumask.h>
#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/sched_clock.h>
#include <linux/mm.h>
#include <clocksource/hyperv_timer.h>
#include <asm/hyperv-tlfs.h>
@@ -198,3 +200,140 @@ void hv_stimer_global_cleanup(void)
hv_stimer_free();
}
EXPORT_SYMBOL_GPL(hv_stimer_global_cleanup);
+
+/*
+ * Code and definitions for the Hyper-V clocksources. Two
+ * clocksources are defined: one that reads the Hyper-V defined MSR, and
+ * the other that uses the TSC reference page feature as defined in the
+ * TLFS. The MSR version is for compatibility with old versions of
+ * Hyper-V and 32-bit x86. The TSC reference page version is preferred.
+ */
+
+struct clocksource *hyperv_cs;
+EXPORT_SYMBOL_GPL(hyperv_cs);
+
+#ifdef CONFIG_HYPERV_TSCPAGE
+
+static struct ms_hyperv_tsc_page *tsc_pg;
+
+struct ms_hyperv_tsc_page *hv_get_tsc_page(void)
+{
+ return tsc_pg;
+}
+EXPORT_SYMBOL_GPL(hv_get_tsc_page);
+
+static u64 notrace read_hv_sched_clock_tsc(void)
+{
+ u64 current_tick = hv_read_tsc_page(tsc_pg);
+
+ if (current_tick == U64_MAX)
+ hv_get_time_ref_count(current_tick);
+
+ return current_tick;
+}
+
+static u64 read_hv_clock_tsc(struct clocksource *arg)
+{
+ return read_hv_sched_clock_tsc();
+}
+
+static struct clocksource hyperv_cs_tsc = {
+ .name = "hyperv_clocksource_tsc_page",
+ .rating = 400,
+ .read = read_hv_clock_tsc,
+ .mask = CLOCKSOURCE_MASK(64),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+#endif
+
+static u64 notrace read_hv_sched_clock_msr(void)
+{
+ u64 current_tick;
+ /*
+ * Read the partition counter to get the current tick count. This count
+ * is set to 0 when the partition is created and is incremented in
+ * 100 nanosecond units.
+ */
+ hv_get_time_ref_count(current_tick);
+ return current_tick;
+}
+
+static u64 read_hv_clock_msr(struct clocksource *arg)
+{
+ return read_hv_sched_clock_msr();
+}
+
+static struct clocksource hyperv_cs_msr = {
+ .name = "hyperv_clocksource_msr",
+ .rating = 400,
+ .read = read_hv_clock_msr,
+ .mask = CLOCKSOURCE_MASK(64),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+#ifdef CONFIG_HYPERV_TSCPAGE
+static bool __init hv_init_tsc_clocksource(void)
+{
+ u64 tsc_msr;
+ phys_addr_t phys_addr;
+
+ if (!(ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE))
+ return false;
+
+ tsc_pg = vmalloc(PAGE_SIZE);
+ if (!tsc_pg)
+ return false;
+
+ hyperv_cs = &hyperv_cs_tsc;
+ phys_addr = page_to_phys(vmalloc_to_page(tsc_pg));
+
+ /*
+ * The Hyper-V TLFS specifies to preserve the value of reserved
+ * bits in registers. So read the existing value, preserve the
+ * low order 12 bits, and add in the guest physical address
+ * (which already has at least the low 12 bits set to zero since
+ * it is page aligned). Also set the "enable" bit, which is bit 0.
+ */
+ hv_get_reference_tsc(tsc_msr);
+ tsc_msr &= GENMASK_ULL(11, 0);
+ tsc_msr = tsc_msr | 0x1 | (u64)phys_addr;
+ hv_set_reference_tsc(tsc_msr);
+
+ hv_set_clocksource_vdso(hyperv_cs_tsc);
+ clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100);
+
+ /* sched_clock_register is needed on ARM64 but is a no-op on x86 */
+ sched_clock_register(read_hv_sched_clock_tsc, 64, HV_CLOCK_HZ);
+ return true;
+}
+#else
+static bool __init hv_init_tsc_clocksource(void)
+{
+ return false;
+}
+#endif
+
+
+void __init hv_init_clocksource(void)
+{
+ /*
+ * Try to set up the TSC page clocksource. If it succeeds, we're
+ * done. Otherwise, set up the MSR clocksoruce. At least one of
+ * these will always be available except on very old versions of
+ * Hyper-V on x86. In that case we won't have a Hyper-V
+ * clocksource, but Linux will still run with a clocksource based
+ * on the emulated PIT or LAPIC timer.
+ */
+ if (hv_init_tsc_clocksource())
+ return;
+
+ if (!(ms_hyperv.features & HV_MSR_TIME_REF_COUNT_AVAILABLE))
+ return;
+
+ hyperv_cs = &hyperv_cs_msr;
+ clocksource_register_hz(&hyperv_cs_msr, NSEC_PER_SEC/100);
+
+ /* sched_clock_register is needed on ARM64 but is a no-op on x86 */
+ sched_clock_register(read_hv_sched_clock_msr, 64, HV_CLOCK_HZ);
+}
+EXPORT_SYMBOL_GPL(hv_init_clocksource);
diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c
index 7d3d31f..e32681e 100644
--- a/drivers/hv/hv_util.c
+++ b/drivers/hv/hv_util.c
@@ -17,6 +17,7 @@
#include <linux/hyperv.h>
#include <linux/clockchips.h>
#include <linux/ptp_clock_kernel.h>
+#include <clocksource/hyperv_timer.h>
#include <asm/mshyperv.h>
#include "hyperv_vmbus.h"
diff --git a/include/clocksource/hyperv_timer.h b/include/clocksource/hyperv_timer.h
index 0cd73f7..ecc044d 100644
--- a/include/clocksource/hyperv_timer.h
+++ b/include/clocksource/hyperv_timer.h
@@ -13,6 +13,10 @@
#ifndef __CLKSOURCE_HYPERV_TIMER_H
#define __CLKSOURCE_HYPERV_TIMER_H
+#include <linux/clocksource.h>
+#include <linux/math64.h>
+#include <asm/mshyperv.h>
+
#define HV_MAX_MAX_DELTA_TICKS 0xffffffff
#define HV_MIN_DELTA_TICKS 1
@@ -24,4 +28,78 @@
extern void hv_stimer_global_cleanup(void);
extern void hv_stimer0_isr(void);
+#if IS_ENABLED(CONFIG_HYPERV)
+extern struct clocksource *hyperv_cs;
+extern void hv_init_clocksource(void);
+#endif /* CONFIG_HYPERV */
+
+#ifdef CONFIG_HYPERV_TSCPAGE
+extern struct ms_hyperv_tsc_page *hv_get_tsc_page(void);
+static inline u64 hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg,
+ u64 *cur_tsc)
+{
+ u64 scale, offset;
+ u32 sequence;
+
+ /*
+ * The protocol for reading Hyper-V TSC page is specified in Hypervisor
+ * Top-Level Functional Specification ver. 3.0 and above. To get the
+ * reference time we must do the following:
+ * - READ ReferenceTscSequence
+ * A special '0' value indicates the time source is unreliable and we
+ * need to use something else. The currently published specification
+ * versions (up to 4.0b) contain a mistake and wrongly claim '-1'
+ * instead of '0' as the special value, see commit c35b82ef0294.
+ * - ReferenceTime =
+ * ((RDTSC() * ReferenceTscScale) >> 64) + ReferenceTscOffset
+ * - READ ReferenceTscSequence again. In case its value has changed
+ * since our first reading we need to discard ReferenceTime and repeat
+ * the whole sequence as the hypervisor was updating the page in
+ * between.
+ */
+ do {
+ sequence = READ_ONCE(tsc_pg->tsc_sequence);
+ if (!sequence)
+ return U64_MAX;
+ /*
+ * Make sure we read sequence before we read other values from
+ * TSC page.
+ */
+ smp_rmb();
+
+ scale = READ_ONCE(tsc_pg->tsc_scale);
+ offset = READ_ONCE(tsc_pg->tsc_offset);
+ *cur_tsc = hv_get_raw_timer();
+
+ /*
+ * Make sure we read sequence after we read all other values
+ * from TSC page.
+ */
+ smp_rmb();
+
+ } while (READ_ONCE(tsc_pg->tsc_sequence) != sequence);
+
+ return mul_u64_u64_shr(*cur_tsc, scale, 64) + offset;
+}
+
+static inline u64 hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg)
+{
+ u64 cur_tsc;
+
+ return hv_read_tsc_page_tsc(tsc_pg, &cur_tsc);
+}
+
+#else /* CONFIG_HYPERV_TSC_PAGE */
+static inline struct ms_hyperv_tsc_page *hv_get_tsc_page(void)
+{
+ return NULL;
+}
+
+static inline u64 hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg,
+ u64 *cur_tsc)
+{
+ return U64_MAX;
+}
+#endif /* CONFIG_HYPERV_TSCPAGE */
+
#endif
--
1.8.3.1
^ permalink raw reply related
* [PATCH v5 0/2] clocksource/drivers: Create new Hyper-V clocksource driver
From: Michael Kelley @ 2019-07-01 4:25 UTC (permalink / raw)
To: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
x86@kernel.org
Cc: Michael Kelley, will.deacon@arm.com, catalin.marinas@arm.com,
mark.rutland@arm.com, linux-arm-kernel@lists.infradead.org,
gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
linux-hyperv@vger.kernel.org, olaf@aepfle.de, apw@canonical.com,
vkuznets, jasowang@redhat.com, marcelo.cerri@canonical.com,
Sunil Muthuswamy, KY Srinivasan, sashal@kernel.org,
vincenzo.frascino@arm.com, linux-arch@vger.kernel.org,
linux-mips@vger.kernel.org, linux-kselftest@vger.kernel.org,
arnd@arndb.de, linux@armlinux.org.uk, ralf@linux-mips.org,
paul.burton@mips.com, daniel.lezcano@linaro.org,
salyzyn@android.com, pcc@google.com, shuah@kernel.org,
0x7f454c46@gmail.com, linux@rasmusvillemoes.dk,
huw@codeweavers.com, sfr@canb.auug.org.au, pbonzini@redhat.com,
rkrcmar@redhat.com, kvm@vger.kernel.org
This patch series moves Hyper-V clock/timer code to a separate Hyper-V
clocksource driver. Previously, Hyper-V clock/timer code and data
structures were mixed in with other Hyper-V code in the ISA independent
drivers/hv code as well as in ISA dependent code. The new Hyper-V
clocksource driver is ISA agnostic, with a just few dependencies on
ISA specific functions. The patch series does not change any behavior
or functionality -- it only reorganizes the existing code and fixes up
the linkages. A few places outside of Hyper-V code are fixed up to use
the new #include file structure.
This restructuring is in response to Marc Zyngier's review comments
on supporting Hyper-V running on ARM64, and is a good idea in general.
It increases the amount of code shared between the x86 and ARM64
architectures, and reduces the size of the new code for supporting
Hyper-V on ARM64. A new version of the Hyper-V on ARM64 patches will
follow once this clocksource restructuring is accepted.
The code is diff'ed against the upstream tip tree:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers/vdso
Changes in v5:
* Revised commit summaries [Thomas Gleixner]
* Removed call to clockevents_unbind_device() [Thomas Gleixner]
* Restructured hv_init_clocksource() [Thomas Gleixner]
* Various other small code cleanups [Thomas Gleixner]
Changes in v4:
* Revised commit messages
* Rebased to upstream tip tree
Changes in v3:
* Removed boolean argument to hv_init_clocksource(). Always call
sched_clock_register, which is needed on ARM64 but a no-op on x86.
* Removed separate cpuhp setup in hv_stimer_alloc() and instead
directly call hv_stimer_init() and hv_stimer_cleanup() from
corresponding VMbus functions. This more closely matches original
code and avoids clocksource stop/restart problems on ARM64 when
VMbus code denies CPU offlining request.
Changes in v2:
* Revised commit short descriptions so the distinction between
the first and second patches is clearer [GregKH]
* Renamed new clocksource driver files and functions to use
existing "timer" and "stimer" names instead of introducing
"syntimer". [Vitaly Kuznetsov]
* Introduced CONFIG_HYPER_TIMER to fix build problem when
CONFIG_HYPERV=m [Vitaly Kuznetsov]
* Added "Suggested-by: Marc Zyngier"
Michael Kelley (2):
clocksource/drivers: Make Hyper-V clocksource ISA agnostic
clocksource/drivers: Continue making Hyper-V clocksource ISA agnostic
MAINTAINERS | 2 +
arch/x86/entry/vdso/vma.c | 2 +-
arch/x86/hyperv/hv_init.c | 91 +--------
arch/x86/include/asm/hyperv-tlfs.h | 6 +
arch/x86/include/asm/mshyperv.h | 81 +-------
arch/x86/include/asm/vdso/gettimeofday.h | 2 +-
arch/x86/kernel/cpu/mshyperv.c | 4 +-
arch/x86/kvm/x86.c | 1 +
drivers/clocksource/Makefile | 1 +
drivers/clocksource/hyperv_timer.c | 339 +++++++++++++++++++++++++++++++
drivers/hv/Kconfig | 3 +
drivers/hv/hv.c | 156 +-------------
drivers/hv/hv_util.c | 1 +
drivers/hv/hyperv_vmbus.h | 3 -
drivers/hv/vmbus_drv.c | 42 ++--
include/clocksource/hyperv_timer.h | 105 ++++++++++
16 files changed, 503 insertions(+), 336 deletions(-)
create mode 100644 drivers/clocksource/hyperv_timer.c
create mode 100644 include/clocksource/hyperv_timer.h
--
1.8.3.1
^ permalink raw reply
* Re: [PATCH] PCI: hv: fix pci-hyperv build, depends on SYSFS
From: Matthew Wilcox @ 2019-07-03 0:15 UTC (permalink / raw)
To: Randy Dunlap
Cc: LKML, linux-hyperv, Jake Oshins, K. Y. Srinivasan, Haiyang Zhang,
Stephen Hemminger, Sasha Levin, linux-pci, Bjorn Helgaas
In-Reply-To: <69c25bc3-da00-2758-92ee-13c82b51fc45@infradead.org>
On Tue, Jul 02, 2019 at 04:24:30PM -0700, Randy Dunlap wrote:
> From: Randy Dunlap <rdunlap@infradead.org>
>
> Fix build errors when building almost-allmodconfig but with SYSFS
> not set (not enabled). Fixes these build errors:
>
> ERROR: "pci_destroy_slot" [drivers/pci/controller/pci-hyperv.ko] undefined!
> ERROR: "pci_create_slot" [drivers/pci/controller/pci-hyperv.ko] undefined!
>
> drivers/pci/slot.o is only built when SYSFS is enabled, so
> pci-hyperv.o has an implicit dependency on SYSFS.
> Make that explicit.
I wonder if we shouldn't rather provide no-op versions of
pci_create|destroy_slot for when SYSFS is not set?
^ permalink raw reply
* [PATCH] PCI: hv: fix pci-hyperv build, depends on SYSFS
From: Randy Dunlap @ 2019-07-02 23:24 UTC (permalink / raw)
To: LKML, linux-hyperv
Cc: Matthew Wilcox, Jake Oshins, K. Y. Srinivasan, Haiyang Zhang,
Stephen Hemminger, Sasha Levin, linux-pci, Bjorn Helgaas
From: Randy Dunlap <rdunlap@infradead.org>
Fix build errors when building almost-allmodconfig but with SYSFS
not set (not enabled). Fixes these build errors:
ERROR: "pci_destroy_slot" [drivers/pci/controller/pci-hyperv.ko] undefined!
ERROR: "pci_create_slot" [drivers/pci/controller/pci-hyperv.ko] undefined!
drivers/pci/slot.o is only built when SYSFS is enabled, so
pci-hyperv.o has an implicit dependency on SYSFS.
Make that explicit.
Also, depending on X86 && X86_64 is not needed, so just change that
to depend on X86_64.
Fixes: 4daace0d8ce8 ("PCI: hv: Add paravirtual PCI front-end for Microsoft Hyper-V VMs")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Jake Oshins <jakeo@microsoft.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: linux-hyperv@vger.kernel.org
---
drivers/pci/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- lnx-52-rc7.orig/drivers/pci/Kconfig
+++ lnx-52-rc7/drivers/pci/Kconfig
@@ -181,7 +181,7 @@ config PCI_LABEL
config PCI_HYPERV
tristate "Hyper-V PCI Frontend"
- depends on X86 && HYPERV && PCI_MSI && PCI_MSI_IRQ_DOMAIN && X86_64
+ depends on X86_64 && HYPERV && PCI_MSI && PCI_MSI_IRQ_DOMAIN && SYSFS
help
The PCI device frontend driver allows the kernel to import arbitrary
PCI devices from a PCI backend to support PCI driver domains.
^ permalink raw reply
* Re: [PATCH] PCI: hv: fix pci-hyperv build, depends on SYSFS
From: Randy Dunlap @ 2019-07-03 3:25 UTC (permalink / raw)
To: Matthew Wilcox
Cc: LKML, linux-hyperv, Jake Oshins, K. Y. Srinivasan, Haiyang Zhang,
Stephen Hemminger, Sasha Levin, linux-pci, Bjorn Helgaas
In-Reply-To: <20190703001541.GG1729@bombadil.infradead.org>
On 7/2/19 5:15 PM, Matthew Wilcox wrote:
> On Tue, Jul 02, 2019 at 04:24:30PM -0700, Randy Dunlap wrote:
>> From: Randy Dunlap <rdunlap@infradead.org>
>>
>> Fix build errors when building almost-allmodconfig but with SYSFS
>> not set (not enabled). Fixes these build errors:
>>
>> ERROR: "pci_destroy_slot" [drivers/pci/controller/pci-hyperv.ko] undefined!
>> ERROR: "pci_create_slot" [drivers/pci/controller/pci-hyperv.ko] undefined!
>>
>> drivers/pci/slot.o is only built when SYSFS is enabled, so
>> pci-hyperv.o has an implicit dependency on SYSFS.
>> Make that explicit.
>
> I wonder if we shouldn't rather provide no-op versions of
> pci_create|destroy_slot for when SYSFS is not set?
>
Makes sense. I'm test-building that now.
--
~Randy
^ permalink raw reply
* RE: [PATCH] PCI: hv: fix pci-hyperv build, depends on SYSFS
From: Dexuan Cui @ 2019-07-03 4:33 UTC (permalink / raw)
To: Randy Dunlap, LKML, linux-hyperv@vger.kernel.org
Cc: Matthew Wilcox, Jake Oshins, KY Srinivasan, Haiyang Zhang,
Stephen Hemminger, Sasha Levin, linux-pci, Bjorn Helgaas
In-Reply-To: <69c25bc3-da00-2758-92ee-13c82b51fc45@infradead.org>
> From: linux-hyperv-owner@vger.kernel.org
> <linux-hyperv-owner@vger.kernel.org> On Behalf Of Randy Dunlap
> Sent: Tuesday, July 2, 2019 4:25 PM
> ERROR: "pci_destroy_slot" [drivers/pci/controller/pci-hyperv.ko] undefined!
> ERROR: "pci_create_slot" [drivers/pci/controller/pci-hyperv.ko] undefined!
>
> drivers/pci/slot.o is only built when SYSFS is enabled, so
> pci-hyperv.o has an implicit dependency on SYSFS.
> Make that explicit.
>
> Also, depending on X86 && X86_64 is not needed, so just change that
> to depend on X86_64.
>
> Fixes: 4daace0d8ce8 ("PCI: hv: Add paravirtual PCI front-end for Microsoft
> Hyper-V VMs")
I think the Fixes tag should be:
Fixes: a15f2c08c708 ("PCI: hv: support reporting serial number as slot information")
Thanks,
-- Dexuan
^ permalink raw reply
* RE: [PATCH] PCI: hv: fix pci-hyperv build, depends on SYSFS
From: Dexuan Cui @ 2019-07-03 4:40 UTC (permalink / raw)
To: Randy Dunlap, Matthew Wilcox, Yuehaibing
Cc: LKML, linux-hyperv@vger.kernel.org, Jake Oshins, KY Srinivasan,
Haiyang Zhang, Stephen Hemminger, Sasha Levin, linux-pci,
Bjorn Helgaas
In-Reply-To: <139b6a64-1980-412b-5870-88706084b288@infradead.org>
> From: linux-hyperv-owner@vger.kernel.org
> <linux-hyperv-owner@vger.kernel.org> On Behalf Of Randy Dunlap
> Sent: Tuesday, July 2, 2019 8:25 PM
> To: Matthew Wilcox <willy@infradead.org>
> Cc: LKML <linux-kernel@vger.kernel.org>; linux-hyperv@vger.kernel.org; Jake
> Oshins <jakeo@microsoft.com>; KY Srinivasan <kys@microsoft.com>; Haiyang
> Zhang <haiyangz@microsoft.com>; Stephen Hemminger
> <sthemmin@microsoft.com>; Sasha Levin <sashal@kernel.org>; linux-pci
> <linux-pci@vger.kernel.org>; Bjorn Helgaas <bhelgaas@google.com>
> Subject: Re: [PATCH] PCI: hv: fix pci-hyperv build, depends on SYSFS
>
> On 7/2/19 5:15 PM, Matthew Wilcox wrote:
> > On Tue, Jul 02, 2019 at 04:24:30PM -0700, Randy Dunlap wrote:
> >> From: Randy Dunlap <rdunlap@infradead.org>
> >>
> >> Fix build errors when building almost-allmodconfig but with SYSFS
> >> not set (not enabled). Fixes these build errors:
> >>
> >> ERROR: "pci_destroy_slot" [drivers/pci/controller/pci-hyperv.ko] undefined!
> >> ERROR: "pci_create_slot" [drivers/pci/controller/pci-hyperv.ko] undefined!
> >>
> >> drivers/pci/slot.o is only built when SYSFS is enabled, so
> >> pci-hyperv.o has an implicit dependency on SYSFS.
> >> Make that explicit.
> >
> > I wonder if we shouldn't rather provide no-op versions of
> > pci_create|destroy_slot for when SYSFS is not set?
> >
>
> Makes sense. I'm test-building that now.
>
> --
> ~Randy
+ Yuehaibing, who submitted a similar patch, which I guess is neglected
at the end of the discussion last month:
https://lkml.org/lkml/2019/5/31/559
https://lkml.org/lkml/2019/6/14/784
https://lkml.org/lkml/2019/6/15/24
Thanks,
-- Dexuan
^ permalink raw reply
* Re: [PATCH] PCI: hv: fix pci-hyperv build, depends on SYSFS
From: Randy Dunlap @ 2019-07-03 5:05 UTC (permalink / raw)
To: Dexuan Cui, LKML, linux-hyperv@vger.kernel.org
Cc: Matthew Wilcox, Jake Oshins, KY Srinivasan, Haiyang Zhang,
Stephen Hemminger, Sasha Levin, linux-pci, Bjorn Helgaas
In-Reply-To: <PU1P153MB016931FDE7BF095FB85783EEBFFB0@PU1P153MB0169.APCP153.PROD.OUTLOOK.COM>
On 7/2/19 9:33 PM, Dexuan Cui wrote:
>> From: linux-hyperv-owner@vger.kernel.org
>> <linux-hyperv-owner@vger.kernel.org> On Behalf Of Randy Dunlap
>> Sent: Tuesday, July 2, 2019 4:25 PM
>> ERROR: "pci_destroy_slot" [drivers/pci/controller/pci-hyperv.ko] undefined!
>> ERROR: "pci_create_slot" [drivers/pci/controller/pci-hyperv.ko] undefined!
>>
>> drivers/pci/slot.o is only built when SYSFS is enabled, so
>> pci-hyperv.o has an implicit dependency on SYSFS.
>> Make that explicit.
>>
>> Also, depending on X86 && X86_64 is not needed, so just change that
>> to depend on X86_64.
>>
>> Fixes: 4daace0d8ce8 ("PCI: hv: Add paravirtual PCI front-end for Microsoft
>> Hyper-V VMs")
>
> I think the Fixes tag should be:
> Fixes: a15f2c08c708 ("PCI: hv: support reporting serial number as slot information")
>
> Thanks,
> -- Dexuan
>
Thanks. I did have a little trouble with that.
--
~Randy
^ permalink raw reply
* [PATCH v2 0/9] x86: Concurrent TLB flushes
From: Nadav Amit @ 2019-07-02 23:51 UTC (permalink / raw)
To: Andy Lutomirski, Dave Hansen
Cc: x86, linux-kernel, Peter Zijlstra, Thomas Gleixner, Ingo Molnar,
Nadav Amit, Borislav Petkov, Boris Ostrovsky, Haiyang Zhang,
Josh Poimboeuf, Juergen Gross, K. Y. Srinivasan, Paolo Bonzini,
Rik van Riel, Sasha Levin, Stephen Hemminger, kvm, linux-hyperv,
virtualization, xen-devel
Currently, local and remote TLB flushes are not performed concurrently,
which introduces unnecessary overhead - each INVLPG can take 100s of
cycles. This patch-set allows TLB flushes to be run concurrently: first
request the remote CPUs to initiate the flush, then run it locally, and
finally wait for the remote CPUs to finish their work.
In addition, there are various small optimizations to avoid unwarranted
false-sharing and atomic operations.
The proposed changes should also improve the performance of other
invocations of on_each_cpu(). Hopefully, no one has relied on this
behavior of on_each_cpu() that invoked functions first remotely and only
then locally [Peter says he remembers someone might do so, but without
further information it is hard to know how to address it].
Running sysbench on dax/ext4 w/emulated-pmem, write-cache disabled on
2-socket, 48-logical-cores (24+SMT) Haswell-X, 5 repetitions:
sysbench fileio --file-total-size=3G --file-test-mode=rndwr \
--file-io-mode=mmap --threads=X --file-fsync-mode=fdatasync run
Th. tip-jun28 avg (stdev) +patch-set avg (stdev) change
--- --------------------- ---------------------- ------
1 1267765 (14146) 1299253 (5715) +2.4%
2 1734644 (11936) 1799225 (19577) +3.7%
4 2821268 (41184) 2919132 (40149) +3.4%
8 4171652 (31243) 4376925 (65416) +4.9%
16 5590729 (24160) 5829866 (8127) +4.2%
24 6250212 (24481) 6522303 (28044) +4.3%
32 3994314 (26606) 4077543 (10685) +2.0%
48 4345177 (28091) 4417821 (41337) +1.6%
(Note that on configurations with up to 24 threads numactl was used to
set all threads on socket 1, which explains the drop in performance when
going to 32 threads).
Running the same benchmark with security mitigations disabled (PTI,
Spectre, MDS):
Th. tip-jun28 avg (stdev) +patch-set avg (stdev) change
--- --------------------- ---------------------- ------
1 1598896 (5174) 1607903 (4091) +0.5%
2 2109472 (17827) 2224726 (4372) +5.4%
4 3448587 (11952) 3668551 (30219) +6.3%
8 5425778 (29641) 5606266 (33519) +3.3%
16 6931232 (34677) 7054052 (27873) +1.7%
24 7612473 (23482) 7783138 (13871) +2.2%
32 4296274 (18029) 4283279 (32323) -0.3%
48 4770029 (35541) 4764760 (13575) -0.1%
Presumably, PTI requires two invalidations of each mapping, which allows
to get higher benefits from concurrency when PTI is on. At the same
time, when mitigations are on, other overheads reduce the potential
speedup.
I tried to reduce the size of the code of the main patch, which required
restructuring of the series.
v1 -> v2:
* Removing the patches that Thomas took [tglx]
* Adding hyper-v, Xen compile-tested implementations [Dave]
* Removing UV [Andy]
* Adding lazy optimization, removing inline keyword [Dave]
* Restructuring patch-set
RFCv2 -> v1:
* Fix comment on flush_tlb_multi [Juergen]
* Removing async invalidation optimizations [Andy]
* Adding KVM support [Paolo]
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm@vger.kernel.org
Cc: linux-hyperv@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Cc: x86@kernel.org
Cc: xen-devel@lists.xenproject.org
Nadav Amit (9):
smp: Run functions concurrently in smp_call_function_many()
x86/mm/tlb: Remove reason as argument for flush_tlb_func_local()
x86/mm/tlb: Open-code on_each_cpu_cond_mask() for tlb_is_not_lazy()
x86/mm/tlb: Flush remote and local TLBs concurrently
x86/mm/tlb: Privatize cpu_tlbstate
x86/mm/tlb: Do not make is_lazy dirty for no reason
cpumask: Mark functions as pure
x86/mm/tlb: Remove UV special case
x86/mm/tlb: Remove unnecessary uses of the inline keyword
arch/x86/hyperv/mmu.c | 13 ++-
arch/x86/include/asm/paravirt.h | 6 +-
arch/x86/include/asm/paravirt_types.h | 4 +-
arch/x86/include/asm/tlbflush.h | 48 +++++----
arch/x86/include/asm/trace/hyperv.h | 2 +-
arch/x86/kernel/kvm.c | 11 +-
arch/x86/kernel/paravirt.c | 2 +-
arch/x86/mm/init.c | 2 +-
arch/x86/mm/tlb.c | 147 ++++++++++++++++----------
arch/x86/xen/mmu_pv.c | 20 ++--
include/linux/cpumask.h | 6 +-
include/linux/smp.h | 27 +++--
include/trace/events/xen.h | 2 +-
kernel/smp.c | 133 +++++++++++------------
14 files changed, 245 insertions(+), 178 deletions(-)
--
2.17.1
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