From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: devel@linuxdriverproject.org, "x86@kernel.org" <x86@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"K. Y. Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Stephen Hemminger <sthemmin@microsoft.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Steven Rostedt <rostedt@goodmis.org>,
Jork Loeser <Jork.Loeser@microsoft.com>,
Simon Xiao <sixiao@microsoft.com>,
Andy Lutomirski <luto@kernel.org>
Subject: Re: [PATCH v7 09/10] x86/hyper-v: support extended CPU ranges for TLB flush hypercalls
Date: Wed, 7 Jun 2017 16:27:09 +0300 [thread overview]
Message-ID: <CAHp75Ve7Pbt5JHe2oYCSkKgxqVYvteWrsJ7r6AOzDsObjTdhHw@mail.gmail.com> (raw)
In-Reply-To: <20170607110101.9912-10-vkuznets@redhat.com>
On Wed, Jun 7, 2017 at 2:01 PM, Vitaly Kuznetsov <vkuznets@redhat.com> wrote:
> Hyper-V hosts may support more than 64 vCPUs, we need to use
> HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX/LIST_EX hypercalls in this
> case.
> +/* HvFlushVirtualAddressSpaceEx, HvFlushVirtualAddressListEx hypercalls */
> +struct hv_flush_pcpu_ex {
> + u64 address_space;
> + u64 flags;
> + struct {
> + u64 format;
> + u64 valid_bank_mask;
> + u64 bank_contents[];
> + } hv_vp_set;
> + u64 gva_list[];
> +};
> +static struct hv_flush_pcpu_ex __percpu *pcpu_flush_ex;
> - flush->address_space = virt_to_phys(mm->pgd);
> + flush->address_space = (u64)virt_to_phys(mm->pgd);
I think this casting is redundant. Your variable fits phys_addr_t
always. Like you do below w/o explicit casting.
> +static void hyperv_flush_tlb_others_ex(const struct cpumask *cpus,
> + struct mm_struct *mm,
> + unsigned long start,
> + unsigned long end)
> +{
> + int nr_bank = 0, max_gvas, gva_n;
> + struct hv_flush_pcpu_ex *flush;
> + u64 status = U64_MAX;
In one of the previous patches you used (u64)ULLONG_MAX.
I recommend to use _there_ same as here, i.e. = U64_MAX;
> + if (mm) {
> + flush->address_space = virt_to_phys(mm->pgd);
No explicit casting is okay here.
> + flush->flags = 0;
> + } else {
> + flush->address_space = 0;
> + flush->flags = HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES;
> + }
> + /*
> + * We can flush not more than max_gvas with one hypercall. Flush the
> + * whole address space if we were asked to do more.
> + */
> + max_gvas = (PAGE_SIZE - sizeof(*flush) -
> + nr_bank * sizeof(flush->hv_vp_set.bank_contents[0])) /
> + sizeof(flush->gva_list[0]);
Is it possible to re-indent like
max_gvas =
(PAGE_SIZE - sizeof(*flush) - nr_bank *
sizeof(flush->hv_vp_set.bank_contents[0])) /
sizeof(flush->gva_list[0]);
for easier understanding the calculus?
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2017-06-07 13:27 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-07 11:00 [PATCH v7 00/10] Hyper-V: paravirtualized remote TLB flushing and hypercall improvements Vitaly Kuznetsov
2017-06-07 11:00 ` [PATCH v7 01/10] x86/hyper-v: include hyperv/ only when CONFIG_HYPERV is set Vitaly Kuznetsov
2017-06-07 11:00 ` [PATCH v7 02/10] x86/hyper-v: stash the max number of virtual/logical processor Vitaly Kuznetsov
2017-06-07 11:00 ` [PATCH v7 03/10] x86/hyper-v: make hv_do_hypercall() inline Vitaly Kuznetsov
2017-06-07 11:00 ` [PATCH v7 04/10] x86/hyper-v: fast hypercall implementation Vitaly Kuznetsov
2017-06-07 11:00 ` [PATCH v7 05/10] hyper-v: use fast hypercall for HVCALL_SIGNAL_EVENT Vitaly Kuznetsov
2017-06-07 11:00 ` [PATCH v7 06/10] x86/hyper-v: implement rep hypercalls Vitaly Kuznetsov
2017-06-07 11:00 ` [PATCH v7 07/10] hyper-v: globalize vp_index Vitaly Kuznetsov
2017-06-07 11:00 ` [PATCH v7 08/10] x86/hyper-v: use hypercall for remote TLB flush Vitaly Kuznetsov
2017-06-07 11:01 ` [PATCH v7 09/10] x86/hyper-v: support extended CPU ranges for TLB flush hypercalls Vitaly Kuznetsov
2017-06-07 13:27 ` Andy Shevchenko [this message]
2017-06-07 11:01 ` [PATCH v7 10/10] tracing/hyper-v: trace hyperv_mmu_flush_tlb_others() Vitaly Kuznetsov
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