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From: KY Srinivasan <kys@microsoft.com>
To: "Roman Kagan" <rkagan@virtuozzo.com>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>,
	"Vitaly Kuznetsov" <vkuznets@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
	"x86@kernel.org" <x86@kernel.org>,
	"Haiyang Zhang" <haiyangz@microsoft.com>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"devel@linuxdriverproject.org" <devel@linuxdriverproject.org>,
	"Denis V . Lunev" <den@openvz.org>
Subject: RE: [PATCH 06/15] hyperv: avoid unnecessary vmalloc
Date: Wed, 21 Dec 2016 19:19:39 +0000	[thread overview]
Message-ID: <DM5PR03MB249020520F8A94171FA9BA99A0930@DM5PR03MB2490.namprd03.prod.outlook.com> (raw)
In-Reply-To: <20161220155602.6298-7-rkagan@virtuozzo.com>



> -----Original Message-----
> From: Roman Kagan [mailto:rkagan@virtuozzo.com]
> Sent: Tuesday, December 20, 2016 7:56 AM
> To: Paolo Bonzini <pbonzini@redhat.com>; Radim Krčmář
> <rkrcmar@redhat.com>; KY Srinivasan <kys@microsoft.com>; Vitaly
> Kuznetsov <vkuznets@redhat.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>; Ingo Molnar
> <mingo@redhat.com>; H. Peter Anvin <hpa@zytor.com>; x86@kernel.org;
> Haiyang Zhang <haiyangz@microsoft.com>; kvm@vger.kernel.org; linux-
> kernel@vger.kernel.org; devel@linuxdriverproject.org; Denis V . Lunev
> <den@openvz.org>; Roman Kagan <rkagan@virtuozzo.com>
> Subject: [PATCH 06/15] hyperv: avoid unnecessary vmalloc
> 
> Make hypercall and tsc page allocation similar to the rest of the
> Hyper-V shared memory stuff instead of vmalloc-ing them.
> 
> Also perform cleanup unconditionally which is safe.
> 
> TODO: the skipping of free in case of a crash is probably no longer
> necessary, too.

Please breakup these patches.
> 
> Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
> ---
>  drivers/hv/hv.c | 42 ++++++++++++++++++------------------------
>  1 file changed, 18 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
> index 6bbc0b09..b40c7d9 100644
> --- a/drivers/hv/hv.c
> +++ b/drivers/hv/hv.c
> @@ -29,6 +29,7 @@
>  #include <linux/version.h>
>  #include <linux/interrupt.h>
>  #include <linux/clockchips.h>
> +#include <asm/cacheflush.h>
>  #include <asm/hyperv.h>
>  #include <asm/mshyperv.h>
>  #include "hyperv_vmbus.h"
> @@ -208,14 +209,15 @@ int hv_init(void)
>  	/* See if the hypercall page is already set */
>  	rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
> 
> -	virtaddr = __vmalloc(PAGE_SIZE, GFP_KERNEL,
> PAGE_KERNEL_EXEC);
> -
> -	if (!virtaddr)
> +	virtaddr = (void *)get_zeroed_page(GFP_KERNEL);
> +	if (!virtaddr || set_memory_x((unsigned long)virtaddr, 1))
>  		goto cleanup;

Have you tested this patch.
> +	hv_context.hypercall_page = virtaddr;
> 
>  	hypercall_msr.enable = 1;
> 
> -	hypercall_msr.guest_physical_address = vmalloc_to_pfn(virtaddr);
> +	hypercall_msr.guest_physical_address =
> +				virt_to_phys(virtaddr) >> PAGE_SHIFT;
>  	wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
> 
>  	/* Confirm that hypercall page did get setup. */
> @@ -225,14 +227,12 @@ int hv_init(void)
>  	if (!hypercall_msr.enable)
>  		goto cleanup;
> 
> -	hv_context.hypercall_page = virtaddr;
> -
>  #ifdef CONFIG_X86_64
>  	if (ms_hyperv.features &
> HV_X64_MSR_REFERENCE_TSC_AVAILABLE) {
>  		union hv_x64_msr_hypercall_contents tsc_msr;
>  		void *va_tsc;
> 
> -		va_tsc = __vmalloc(PAGE_SIZE, GFP_KERNEL,
> PAGE_KERNEL);
> +		va_tsc = (void *)get_zeroed_page(GFP_KERNEL);
>  		if (!va_tsc)
>  			goto cleanup;
>  		hv_context.tsc_page = va_tsc;
> @@ -240,7 +240,8 @@ int hv_init(void)
>  		rdmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
> 
>  		tsc_msr.enable = 1;
> -		tsc_msr.guest_physical_address = vmalloc_to_pfn(va_tsc);
> +		tsc_msr.guest_physical_address =
> +				virt_to_phys(va_tsc) >> PAGE_SHIFT;
> 
>  		wrmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
>  		clocksource_register_hz(&hyperv_cs_tsc,
> NSEC_PER_SEC/100);
> @@ -249,14 +250,9 @@ int hv_init(void)
>  	return 0;
> 
>  cleanup:
> -	if (virtaddr) {
> -		if (hypercall_msr.enable) {
> -			hypercall_msr.as_uint64 = 0;
> -			wrmsrl(HV_X64_MSR_HYPERCALL,
> hypercall_msr.as_uint64);
> -		}
> -
> -		vfree(virtaddr);
> -	}
> +	hypercall_msr.as_uint64 = 0;
> +	wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
> +	free_page((unsigned long)virtaddr);
> 
>  	return -ENOTSUPP;
>  }
> @@ -273,13 +269,11 @@ void hv_cleanup(bool crash)
>  	/* Reset our OS id */
>  	wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
> 
> -	if (hv_context.hypercall_page) {
> -		hypercall_msr.as_uint64 = 0;
> -		wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
> -		if (!crash)
> -			vfree(hv_context.hypercall_page);
> -		hv_context.hypercall_page = NULL;
> -	}
> +	hypercall_msr.as_uint64 = 0;
> +	wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
> +	if (!crash)
> +		free_page((unsigned long)hv_context.hypercall_page);
> +	hv_context.hypercall_page = NULL;
> 
>  #ifdef CONFIG_X86_64
>  	/*
> @@ -298,7 +292,7 @@ void hv_cleanup(bool crash)
>  		hypercall_msr.as_uint64 = 0;
>  		wrmsrl(HV_X64_MSR_REFERENCE_TSC,
> hypercall_msr.as_uint64);
>  		if (!crash)
> -			vfree(hv_context.tsc_page);
> +			free_page((unsigned long)hv_context.tsc_page);
>  		hv_context.tsc_page = NULL;
>  	}
>  #endif
> --
> 2.9.3

  reply	other threads:[~2016-12-21 19:19 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-12-20 15:55 [PATCH 00/15] hyperv: more stuff to uapi + cleanup Roman Kagan
2016-12-20 15:55 ` [PATCH 01/15] hyperv: consolidate TSC ref page definitions Roman Kagan
2016-12-20 20:57   ` KY Srinivasan
2016-12-21  6:25     ` Roman Kagan
2016-12-20 15:55 ` [PATCH 02/15] hyperv: uapi-fy synic event flags definitions Roman Kagan
2016-12-20 17:24   ` Stephen Hemminger
2016-12-21  6:33     ` Roman Kagan
2016-12-21 10:58   ` kbuild test robot
2016-12-21 18:58   ` KY Srinivasan
2016-12-20 15:55 ` [PATCH 03/15] hyperv: use standard bitops Roman Kagan
2016-12-21 12:00   ` Olaf Hering
2016-12-21 13:23     ` Roman Kagan
2016-12-22 12:33       ` Paolo Bonzini
2016-12-21 19:08   ` KY Srinivasan
2016-12-20 15:55 ` [PATCH 04/15] hyperv: define VMBus message type Roman Kagan
2016-12-20 15:55 ` [PATCH 05/15] hyperv: GFP_ATOMIC -> GFP_KERNEL Roman Kagan
2016-12-20 15:55 ` [PATCH 06/15] hyperv: avoid unnecessary vmalloc Roman Kagan
2016-12-21 19:19   ` KY Srinivasan [this message]
2016-12-20 15:55 ` [PATCH 07/15] hyperv: dedup cpuid definitions Roman Kagan
2016-12-20 15:55 ` [PATCH 08/15] hyperv: dedup crash msr related definitions Roman Kagan
2016-12-20 15:55 ` [PATCH 09/15] hyperv: unify Hyper-V msr definitions Roman Kagan
2016-12-20 15:55 ` [PATCH 10/15] hyperv: uapi-fy PostMessage and SignalEvent hypercall structures Roman Kagan
2016-12-21 19:27   ` KY Srinivasan
2016-12-20 15:55 ` [PATCH 11/15] hyperv: uapi-fy monitored notification structures Roman Kagan
2016-12-20 15:55 ` [PATCH 12/15] hyperv: move VMBus connection ids to uapi Roman Kagan
2016-12-20 17:25   ` Stephen Hemminger
2016-12-21  6:29     ` Roman Kagan
2016-12-21 12:18       ` Christoph Hellwig
2016-12-21 12:59         ` Roman Kagan
2016-12-21 14:26           ` Christoph Hellwig
2016-12-21 14:39             ` Roman Kagan
2016-12-21 15:39             ` Paolo Bonzini
2016-12-21 15:43               ` Christoph Hellwig
2016-12-21 17:25                 ` Paolo Bonzini
2016-12-21 17:50                 ` Stephen Hemminger
2016-12-21 17:53                   ` Paolo Bonzini
2016-12-21 17:58                   ` Christoph Hellwig
2016-12-21 18:02                     ` Stephen Hemminger
2016-12-21 19:54                       ` KY Srinivasan
2016-12-28 17:09                         ` Roman Kagan
2016-12-29 18:29                           ` Stephen Hemminger
2017-01-02  8:19                           ` Paolo Bonzini
2017-01-09  8:32                             ` Roman Kagan
2017-01-09  8:40                               ` hpa
2017-01-09  8:58                                 ` Roman Kagan
2017-01-09  9:02                                 ` Paolo Bonzini
2017-01-02 19:39                           ` Stephen Hemminger
2017-01-03  9:32                             ` Paolo Bonzini
2016-12-20 15:56 ` [PATCH 13/15] hyperv: move function close to its only callsite Roman Kagan
2016-12-20 15:56 ` [PATCH 14/15] hyperv_vmbus: drop unused definitions Roman Kagan
2016-12-20 15:56 ` [PATCH 15/15] hyperv: redefine hv_message without bitfields Roman Kagan
2016-12-21 18:00 ` [PATCH 00/15] hyperv: more stuff to uapi + cleanup KY Srinivasan
2016-12-28 16:57   ` Roman Kagan
2016-12-30 19:45     ` KY Srinivasan

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