|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 2/6] xc: use XENMEM_claim_pages during guest creation.
On Mon, 2013-03-11 at 14:20 +0000, Konrad Rzeszutek Wilk wrote:
> From: Dan Magenheimer <dan.magenheimer@xxxxxxxxxx>
>
> We add an extra parameter to the structures passed to the
> PV routine (arch_setup_meminit) and HVM routine (setup_guest)
> that determines whether the claim hypercall is to be done.
>
> The contents of the 'claim_mode' is defined as an 'uint8_t'
> in case the hypercall expands in the future with extra
> flags (for example for per-NUMA allocation). For right now
> the proper values are: 0 to disable it or 1 to enable
> it.
At the hypercall layer mem_flags is 32 bits, while this is only 8? But
also it seems that claim_mode at the libxc layer doesn't really
correspond directly to mem_flags anyway, which this commentary seems to
suggest it somehow does.
I think it would be less confusing to just have "int claim_enabled" for
now and add a claim_flags if and when they come into being.
>
> Signed-off-by: Dan Magenheimer <dan.magenheimer@xxxxxxxxxx>
> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
> ---
> tools/libxc/xc_dom.h | 1 +
> tools/libxc/xc_dom_x86.c | 12 ++++++++++++
> tools/libxc/xc_domain.c | 24 ++++++++++++++++++++++++
> tools/libxc/xc_hvm_build_x86.c | 17 +++++++++++++++++
> tools/libxc/xenctrl.h | 6 ++++++
> tools/libxc/xenguest.h | 2 ++
> 6 files changed, 62 insertions(+)
>
> diff --git a/tools/libxc/xc_dom.h b/tools/libxc/xc_dom.h
> index 779b9d4..34a6e38 100644
> --- a/tools/libxc/xc_dom.h
> +++ b/tools/libxc/xc_dom.h
> @@ -135,6 +135,7 @@ struct xc_dom_image {
> domid_t guest_domid;
> int8_t vhpt_size_log2; /* for IA64 */
> int8_t superpages;
> + uint8_t claim_mode; /* 0 by default disables it, 1 enables it */
> int shadow_enabled;
>
> int xen_version;
> diff --git a/tools/libxc/xc_dom_x86.c b/tools/libxc/xc_dom_x86.c
> index eb9ac07..c1b7905 100644
> --- a/tools/libxc/xc_dom_x86.c
> +++ b/tools/libxc/xc_dom_x86.c
> @@ -706,6 +706,13 @@ int arch_setup_meminit(struct xc_dom_image *dom)
> }
> else
> {
> + /* try to claim pages for early warning of insufficient memory avail
> */
> + if ( dom->claim_mode ) {
> + rc = xc_domain_claim_pages(dom->xch, dom->guest_domid,
> + dom->total_pages);
> + if ( rc )
> + return rc;
> + }
> /* setup initial p2m */
> for ( pfn = 0; pfn < dom->total_pages; pfn++ )
> dom->p2m_host[pfn] = pfn;
> @@ -722,6 +729,11 @@ int arch_setup_meminit(struct xc_dom_image *dom)
> dom->xch, dom->guest_domid, allocsz,
> 0, 0, &dom->p2m_host[i]);
> }
> +
> + /* Ensure no unclaimed pages are left unused.
> + * OK to call if hadn't done the earlier claim call. */
> + xc_domain_claim_pages(dom->xch, dom->guest_domid,
> + 0 /* cancels the claim */);
> }
>
> return rc;
> diff --git a/tools/libxc/xc_domain.c b/tools/libxc/xc_domain.c
> index 480ce91..b8a345c 100644
> --- a/tools/libxc/xc_domain.c
> +++ b/tools/libxc/xc_domain.c
> @@ -775,6 +775,30 @@ int xc_domain_add_to_physmap(xc_interface *xch,
> return do_memory_op(xch, XENMEM_add_to_physmap, &xatp, sizeof(xatp));
> }
>
> +int xc_domain_claim_pages(xc_interface *xch,
> + uint32_t domid,
> + unsigned long nr_pages)
> +{
> + int err;
> + xen_pfn_t *extent_start = NULL;
> + DECLARE_HYPERCALL_BOUNCE(extent_start, 0,
> XC_HYPERCALL_BUFFER_BOUNCE_BOTH);
> + struct xen_memory_reservation reservation = {
> + .nr_extents = nr_pages,
> + .extent_order = 0,
> + .mem_flags = 0, /* no flags */
> + .domid = domid
> + };
> +
> + set_xen_guest_handle(reservation.extent_start, extent_start);
This is unused? I think you just need:
set_xen_guest_handle(reservation.extent_start, HYPERCALL_BUFFER_NULL);
and drop the declaration of the bounce above.
(personally I think a new arg struct for this subop would have been more
obvious than forcing it into the reservation struct, but what's done is
done)
> + err = do_memory_op(xch, XENMEM_claim_pages, &reservation,
> sizeof(reservation));
> + return err;
> +}
> +unsigned long xc_domain_get_outstanding_pages(xc_interface *xch)
> +{
> + return do_memory_op(xch, XENMEM_get_outstanding_pages, NULL, 0);
> +}
> +
> int xc_domain_populate_physmap(xc_interface *xch,
> uint32_t domid,
> unsigned long nr_extents,
> diff --git a/tools/libxc/xc_hvm_build_x86.c b/tools/libxc/xc_hvm_build_x86.c
> index 3b5d777..b6b56b3 100644
> --- a/tools/libxc/xc_hvm_build_x86.c
> +++ b/tools/libxc/xc_hvm_build_x86.c
> @@ -252,6 +252,7 @@ static int setup_guest(xc_interface *xch,
> unsigned long stat_normal_pages = 0, stat_2mb_pages = 0,
> stat_1gb_pages = 0;
> int pod_mode = 0;
> + unsigned int claim_mode = args->claim_mode;
>
> if ( nr_pages > target_pages )
> pod_mode = XENMEMF_populate_on_demand;
> @@ -329,6 +330,16 @@ static int setup_guest(xc_interface *xch,
> xch, dom, 0xa0, 0, pod_mode, &page_array[0x00]);
> cur_pages = 0xc0;
> stat_normal_pages = 0xc0;
> +
> + /* try to claim pages for early warning of insufficient memory available
> */
> + if ( claim_mode ) {
> + rc = xc_domain_claim_pages(xch, dom, nr_pages - cur_pages);
> + if ( rc != 0 )
> + {
> + PERROR("Could not allocate memory for HVM guest.");
> + goto error_out;
> + }
> + }
> while ( (rc == 0) && (nr_pages > cur_pages) )
> {
> /* Clip count to maximum 1GB extent. */
> @@ -506,10 +517,16 @@ static int setup_guest(xc_interface *xch,
> munmap(page0, PAGE_SIZE);
> }
>
> + /* ensure no unclaimed pages are left unused */
> + xc_domain_claim_pages(xch, dom, 0 /* cancels the claim */);
This cannot fail?
> +
> free(page_array);
> return 0;
>
> error_out:
> + /* ensure no unclaimed pages are left unused */
> + xc_domain_claim_pages(xch, dom, 0 /* cancels the claim */);
> +
> free(page_array);
> return -1;
Could we consolidate the error/success paths by returning rc?
> }
> diff --git a/tools/libxc/xenctrl.h b/tools/libxc/xenctrl.h
> index 32122fd..e695456 100644
> --- a/tools/libxc/xenctrl.h
> +++ b/tools/libxc/xenctrl.h
> @@ -1129,6 +1129,12 @@ int xc_domain_populate_physmap_exact(xc_interface *xch,
> unsigned int mem_flags,
> xen_pfn_t *extent_start);
>
> +int xc_domain_claim_pages(xc_interface *xch,
> + uint32_t domid,
> + unsigned long nr_pages);
> +
> +unsigned long xc_domain_get_outstanding_pages(xc_interface *xch);
> +
> int xc_domain_memory_exchange_pages(xc_interface *xch,
> int domid,
> unsigned long nr_in_extents,
> diff --git a/tools/libxc/xenguest.h b/tools/libxc/xenguest.h
> index 7d4ac33..e3c879b 100644
> --- a/tools/libxc/xenguest.h
> +++ b/tools/libxc/xenguest.h
> @@ -231,6 +231,8 @@ struct xc_hvm_build_args {
>
> /* Extra SMBIOS structures passed to HVMLOADER */
> struct xc_hvm_firmware_module smbios_module;
> + /* Whether to use claim hypercall (1 - enable, 0 - disable). */
> + uint8_t claim_mode;
> };
>
> /**
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel
|
 |
Lists.xenproject.org is hosted with RackSpace, monitoring our |