From: Michael Kelley <mikelley@microsoft.com>
To: Wei Liu <wei.liu@kernel.org>,
Linux on Hyper-V List <linux-hyperv@vger.kernel.org>
Cc: "virtualization@lists.linux-foundation.org"
<virtualization@lists.linux-foundation.org>,
Linux Kernel List <linux-kernel@vger.kernel.org>,
Vineeth Pillai <viremana@linux.microsoft.com>,
Sunil Muthuswamy <sunilmut@microsoft.com>,
Nuno Das Neves <nunodasneves@linux.microsoft.com>,
"pasha.tatashin@soleen.com" <pasha.tatashin@soleen.com>,
Lillian Grassin-Drake <Lillian.GrassinDrake@microsoft.com>,
KY Srinivasan <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Stephen Hemminger <sthemmin@microsoft.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
<x86@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>
Subject: RE: [PATCH v6 05/16] x86/hyperv: allocate output arg pages if required
Date: Thu, 4 Feb 2021 16:52:59 +0000 [thread overview]
Message-ID: <MWHPR21MB1593AF12B03D431705E1297BD7B39@MWHPR21MB1593.namprd21.prod.outlook.com> (raw)
In-Reply-To: <20210203150435.27941-6-wei.liu@kernel.org>
From: Wei Liu <wei.liu@kernel.org> Sent: Wednesday, February 3, 2021 7:04 AM
>
> When Linux runs as the root partition, it will need to make hypercalls
> which return data from the hypervisor.
>
> Allocate pages for storing results when Linux runs as the root
> partition.
>
> Signed-off-by: Lillian Grassin-Drake <ligrassi@microsoft.com>
> Co-Developed-by: Lillian Grassin-Drake <ligrassi@microsoft.com>
> Signed-off-by: Wei Liu <wei.liu@kernel.org>
> ---
> v3: Fix hv_cpu_die to use free_pages.
> v2: Address Vitaly's comments
> ---
> arch/x86/hyperv/hv_init.c | 35 ++++++++++++++++++++++++++++-----
> arch/x86/include/asm/mshyperv.h | 1 +
> 2 files changed, 31 insertions(+), 5 deletions(-)
>
> diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
> index e04d90af4c27..6f4cb40e53fe 100644
> --- a/arch/x86/hyperv/hv_init.c
> +++ b/arch/x86/hyperv/hv_init.c
> @@ -41,6 +41,9 @@ EXPORT_SYMBOL_GPL(hv_vp_assist_page);
> void __percpu **hyperv_pcpu_input_arg;
> EXPORT_SYMBOL_GPL(hyperv_pcpu_input_arg);
>
> +void __percpu **hyperv_pcpu_output_arg;
> +EXPORT_SYMBOL_GPL(hyperv_pcpu_output_arg);
> +
> u32 hv_max_vp_index;
> EXPORT_SYMBOL_GPL(hv_max_vp_index);
>
> @@ -73,12 +76,19 @@ static int hv_cpu_init(unsigned int cpu)
> void **input_arg;
> struct page *pg;
>
> - input_arg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
> /* hv_cpu_init() can be called with IRQs disabled from hv_resume() */
> - pg = alloc_page(irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL);
> + pg = alloc_pages(irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL, hv_root_partition ? 1 : 0);
> if (unlikely(!pg))
> return -ENOMEM;
> +
> + input_arg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
> *input_arg = page_address(pg);
> + if (hv_root_partition) {
> + void **output_arg;
> +
> + output_arg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg);
> + *output_arg = page_address(pg + 1);
> + }
>
> hv_get_vp_index(msr_vp_index);
>
> @@ -205,14 +215,23 @@ static int hv_cpu_die(unsigned int cpu)
> unsigned int new_cpu;
> unsigned long flags;
> void **input_arg;
> - void *input_pg = NULL;
> + void *pg;
>
> local_irq_save(flags);
> input_arg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
> - input_pg = *input_arg;
> + pg = *input_arg;
> *input_arg = NULL;
> +
> + if (hv_root_partition) {
> + void **output_arg;
> +
> + output_arg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg);
> + *output_arg = NULL;
> + }
> +
> local_irq_restore(flags);
> - free_page((unsigned long)input_pg);
> +
> + free_pages((unsigned long)pg, hv_root_partition ? 1 : 0);
>
> if (hv_vp_assist_page && hv_vp_assist_page[cpu])
> wrmsrl(HV_X64_MSR_VP_ASSIST_PAGE, 0);
> @@ -346,6 +365,12 @@ void __init hyperv_init(void)
>
> BUG_ON(hyperv_pcpu_input_arg == NULL);
>
> + /* Allocate the per-CPU state for output arg for root */
> + if (hv_root_partition) {
> + hyperv_pcpu_output_arg = alloc_percpu(void *);
> + BUG_ON(hyperv_pcpu_output_arg == NULL);
> + }
> +
> /* Allocate percpu VP index */
> hv_vp_index = kmalloc_array(num_possible_cpus(), sizeof(*hv_vp_index),
> GFP_KERNEL);
> diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
> index ac2b0d110f03..62d9390f1ddf 100644
> --- a/arch/x86/include/asm/mshyperv.h
> +++ b/arch/x86/include/asm/mshyperv.h
> @@ -76,6 +76,7 @@ static inline void hv_disable_stimer0_percpu_irq(int irq) {}
> #if IS_ENABLED(CONFIG_HYPERV)
> extern void *hv_hypercall_pg;
> extern void __percpu **hyperv_pcpu_input_arg;
> +extern void __percpu **hyperv_pcpu_output_arg;
>
> static inline u64 hv_do_hypercall(u64 control, void *input, void *output)
> {
> --
> 2.20.1
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
next prev parent reply other threads:[~2021-02-04 16:56 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-03 15:04 [PATCH v6 00/16] Introducing Linux root partition support for Microsoft Hypervisor Wei Liu
2021-02-03 15:04 ` [PATCH v6 01/16] asm-generic/hyperv: change HV_CPU_POWER_MANAGEMENT to HV_CPU_MANAGEMENT Wei Liu
2021-02-03 15:04 ` [PATCH v6 02/16] x86/hyperv: detect if Linux is the root partition Wei Liu
2021-02-04 16:49 ` Michael Kelley
2021-02-03 15:04 ` [PATCH v6 03/16] Drivers: hv: vmbus: skip VMBus initialization if Linux is root Wei Liu
2021-02-03 15:04 ` [PATCH v6 04/16] clocksource/hyperv: use MSR-based access if running as root Wei Liu
2021-02-03 15:04 ` [PATCH v6 05/16] x86/hyperv: allocate output arg pages if required Wei Liu
2021-02-04 16:52 ` Michael Kelley [this message]
2021-02-03 15:04 ` [PATCH v6 06/16] x86/hyperv: extract partition ID from Microsoft Hypervisor if necessary Wei Liu
2021-02-04 16:54 ` Michael Kelley
2021-02-03 15:04 ` [PATCH v6 07/16] x86/hyperv: handling hypercall page setup for root Wei Liu
2021-02-03 15:04 ` [PATCH v6 08/16] ACPI / NUMA: add a stub function for node_to_pxm() Wei Liu
2021-02-04 18:38 ` Wei Liu
2021-02-04 18:45 ` Rafael J. Wysocki
2021-02-04 18:48 ` Wei Liu
2021-02-03 15:04 ` [PATCH v6 09/16] x86/hyperv: provide a bunch of helper functions Wei Liu
2021-02-04 17:13 ` Michael Kelley
2021-02-03 15:04 ` [PATCH v6 10/16] x86/hyperv: implement and use hv_smp_prepare_cpus Wei Liu
2021-02-03 15:04 ` [PATCH v6 11/16] asm-generic/hyperv: update hv_msi_entry Wei Liu
2021-02-03 15:04 ` [PATCH v6 12/16] asm-generic/hyperv: update hv_interrupt_entry Wei Liu
2021-02-03 15:04 ` [PATCH v6 13/16] asm-generic/hyperv: introduce hv_device_id and auxiliary structures Wei Liu
2021-02-04 17:15 ` Michael Kelley
2021-02-03 15:04 ` [PATCH v6 14/16] asm-generic/hyperv: import data structures for mapping device interrupts Wei Liu
2021-02-03 15:04 ` [PATCH v6 15/16] x86/hyperv: implement an MSI domain for root partition Wei Liu
2021-02-04 17:43 ` Michael Kelley
2021-02-04 17:56 ` Wei Liu
2021-02-04 18:40 ` Michael Kelley
2021-02-04 18:43 ` Wei Liu
2021-02-03 15:04 ` [PATCH v6 16/16] iommu/hyperv: setup an IO-APIC IRQ remapping " Wei Liu
2021-02-04 13:33 ` Joerg Roedel
2021-02-04 17:53 ` Michael Kelley
2021-02-04 19:49 ` [PATCH v6 00/16] Introducing Linux root partition support for Microsoft Hypervisor Wei Liu
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