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From: Paolo Bonzini <pbonzini@redhat.com>
To: Alexey Kardashevskiy <aik@ozlabs.ru>, qemu-devel@nongnu.org
Cc: Alex Williamson <alex.williamson@redhat.com>,
	Alexander Graf <agraf@suse.de>
Subject: Re: [Qemu-devel] [PATCH qemu] kvm-all: Align to qemu_real_host_page_size in kvm_set_phys_mem
Date: Wed, 7 Oct 2015 12:52:16 +0200	[thread overview]
Message-ID: <5614F960.9080703@redhat.com> (raw)
In-Reply-To: <1444102257-17405-1-git-send-email-aik@ozlabs.ru>



On 06/10/2015 05:30, Alexey Kardashevskiy wrote:
> As the comment in kvm_set_phys_mem() says, KVM works in page size chunks.
> However it uses hardcoded TARGET_PAGE_SIZE which is 4K on most platforms
> while actual host may use different page size, for example, PPC64 hosts
> use 64K system pages.
> 
> This replaces static TARGET_PAGE_SIZE with run-time calculated
> qemu_real_host_page_size.
> 
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> ---
> 
> This is the result of debugging VFIO quirks not working under PPC64 KVM.
> ---
>  kvm-all.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/kvm-all.c b/kvm-all.c
> index 0be4615..6f04fbb 100644
> --- a/kvm-all.c
> +++ b/kvm-all.c
> @@ -642,15 +642,15 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml,
>      /* kvm works in page size chunks, but the function may be called
>         with sub-page size and unaligned start address. Pad the start
>         address to next and truncate size to previous page boundary. */
> -    delta = (TARGET_PAGE_SIZE - (start_addr & ~TARGET_PAGE_MASK));
> -    delta &= ~TARGET_PAGE_MASK;
> +    delta = qemu_real_host_page_size - (start_addr & ~qemu_real_host_page_mask);
> +    delta &= ~qemu_real_host_page_mask;
>      if (delta > size) {
>          return;
>      }
>      start_addr += delta;
>      size -= delta;
> -    size &= TARGET_PAGE_MASK;
> -    if (!size || (start_addr & ~TARGET_PAGE_MASK)) {
> +    size &= qemu_real_host_page_mask;
> +    if (!size || (start_addr & ~qemu_real_host_page_mask)) {
>          return;
>      }
>  
> 

Queued, thanks.

Paolo

      reply	other threads:[~2015-10-07 10:52 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-06  3:30 [Qemu-devel] [PATCH qemu] kvm-all: Align to qemu_real_host_page_size in kvm_set_phys_mem Alexey Kardashevskiy
2015-10-07 10:52 ` Paolo Bonzini [this message]

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