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From: Andrew Jones <drjones@redhat.com>
To: Ben Gardon <bgardon@google.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	linux-kselftest@vger.kernel.org,
	Paolo Bonzini <pbonzini@redhat.com>,
	Cannon Matthews <cannonmatthews@google.com>,
	Peter Xu <peterx@redhat.com>, Peter Shier <pshier@google.com>,
	Oliver Upton <oupton@google.com>
Subject: Re: [PATCH v4 07/10] KVM: selftests: Support multiple vCPUs in demand paging test
Date: Fri, 24 Jan 2020 11:49:43 +0100
Message-ID: <20200124104943.6abkjzegmewnoeiv@kamzik.brq.redhat.com> (raw)
In-Reply-To: <20200123180436.99487-8-bgardon@google.com>

On Thu, Jan 23, 2020 at 10:04:33AM -0800, Ben Gardon wrote:
...
> -static struct kvm_vm *create_vm(enum vm_guest_mode mode, uint32_t vcpuid,
> -				uint64_t extra_mem_pages, void *guest_code)
> +#define PAGE_SHIFT_4K  12
> +#define PTES_PER_4K_PT 512
> +
> +static struct kvm_vm *create_vm(enum vm_guest_mode mode, int vcpus,
> +				uint64_t vcpu_memory_bytes)
>  {
>  	struct kvm_vm *vm;
> -	uint64_t extra_pg_pages = extra_mem_pages / 512 * 2;
> +	uint64_t pages = DEFAULT_GUEST_PHY_PAGES;
> +
> +	/* Account for a few pages per-vCPU for stacks */
> +	pages += DEFAULT_STACK_PGS * vcpus;
> +
> +	/*
> +	 * Reserve twice the ammount of memory needed to map the test region and
> +	 * the page table / stacks region, at 4k, for page tables. Do the
> +	 * calculation with 4K page size: the smallest of all archs. (e.g., 64K
> +	 * page size guest will need even less memory for page tables).
> +	 */
> +	pages += (2 * pages) / PTES_PER_4K_PT;
> +	pages += ((2 * vcpus * vcpu_memory_bytes) >> PAGE_SHIFT_4K) /
> +		 PTES_PER_4K_PT;

pages needs to be rounded up to the next multiple of 16 in order for this
to work on aarch64 machines with 64k pages.

Thanks,
drew


  parent reply index

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-23 18:04 [PATCH v4 00/10] Create a userfaultfd " Ben Gardon
2020-01-23 18:04 ` [PATCH v4 01/10] KVM: selftests: Create a " Ben Gardon
2020-01-24  9:49   ` Andrew Jones
2020-01-27  9:18   ` Thomas Huth
2020-01-23 18:04 ` [PATCH v4 02/10] KVM: selftests: Add demand paging content to the " Ben Gardon
2020-01-23 18:04 ` [PATCH v4 03/10] KVM: selftests: Add configurable demand paging delay Ben Gardon
2020-01-23 18:04 ` [PATCH v4 04/10] KVM: selftests: Add memory size parameter to the demand paging test Ben Gardon
2020-01-24 10:01   ` Andrew Jones
2020-01-23 18:04 ` [PATCH v4 05/10] KVM: selftests: Pass args to vCPU in global vCPU args struct Ben Gardon
2020-01-23 18:04 ` [PATCH v4 06/10] KVM: selftests: Add support for vcpu_args_set to aarch64 and s390x Ben Gardon
2020-01-24  9:03   ` Paolo Bonzini
2020-01-24  9:35     ` Andrew Jones
2020-01-24  9:44       ` Paolo Bonzini
2020-01-24 10:45       ` Andrew Jones
2020-01-24 18:33     ` Christian Borntraeger
2020-01-25  9:34   ` Paolo Bonzini
2020-01-27  8:38     ` Andrew Jones
2020-01-27  9:01   ` Thomas Huth
2020-01-23 18:04 ` [PATCH v4 07/10] KVM: selftests: Support multiple vCPUs in demand paging test Ben Gardon
2020-01-24 10:16   ` Andrew Jones
2020-01-24 10:49   ` Andrew Jones [this message]
2020-01-25  9:39     ` Paolo Bonzini
2020-01-27  8:39       ` Andrew Jones
2020-01-23 18:04 ` [PATCH v4 08/10] KVM: selftests: Time guest demand paging Ben Gardon
2020-01-24 10:21   ` Andrew Jones
2020-01-23 18:04 ` [PATCH v4 09/10] KVM: selftests: Stop memslot creation in KVM internal memslot region Ben Gardon
2020-01-24  8:58   ` Paolo Bonzini
2020-01-24 18:41     ` Ben Gardon
2020-01-25  9:37       ` Paolo Bonzini
2020-01-27 17:28         ` Ben Gardon
2020-01-23 18:04 ` [PATCH v4 10/10] KVM: selftests: Move memslot 0 above KVM internal memslots Ben Gardon
2020-01-24  9:01   ` Paolo Bonzini
2020-01-24 18:53     ` Ben Gardon
2020-01-27  9:42   ` Thomas Huth
2020-01-24  9:03 ` [PATCH v4 00/10] Create a userfaultfd demand paging test Paolo Bonzini

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