[libvirt] [PATCH 1/2] libxl: add support for PVH
Jim Fehlig
jfehlig at suse.com
Sat Sep 17 15:16:57 UTC 2016
On 09/16/2016 05:14 PM, Marek Marczykowski-Górecki wrote:
> On Fri, Sep 16, 2016 at 04:39:23PM -0600, Jim Fehlig wrote:
>> On 08/05/2016 12:05 PM, Marek Marczykowski-Górecki wrote:
>>> Since this is something between PV and HVM, it makes sense to put the
>>> setting in place where domain type is specified.
>>> To enable it, use <os><type machine="xenpvh">...</type></os>. It is
>>> also included in capabilities.xml, for every supported HVM guest type - it
>>> doesn't seems to be any other requirement (besides new enough Xen).
>>>
>>> Signed-off-by: Marek Marczykowski-Górecki <marmarek at invisiblethingslab.com>
>>> ---
>>> src/libxl/libxl_capabilities.c | 40 +++++++++++++++++++++++++++++++---------
>>> src/libxl/libxl_conf.c | 2 ++
>>> src/libxl/libxl_driver.c | 6 ++++--
>>> 3 files changed, 37 insertions(+), 11 deletions(-)
>> I didn't investigate, but this patch did not apply cleanly.
>>
>> Does 'xenpvh' need to be added to docs/schema/domaincommon.rng? The schema looks
>> dated anyhow since it currently contains 'xenpv' and 'xenner'. And perhaps this
>> value should be added to docs/formatdomain.html.in, along with a sentence about
>> the possible values for Xen machines.
> After further evaluation[1], PVHv1 is not the thing I wanted here. And
> PVHv2 is going to be significantly different. While this patch do work
> for me, I'm not going to spend more time on PVHv1.
Ok. I'm not a fan of supporting PVHv1 in libvirt anyhow. It came and went before
anyone even used it :-).
>
>>> diff --git a/src/libxl/libxl_capabilities.c b/src/libxl/libxl_capabilities.c
>>> index 0145116..c443353 100644
>>> --- a/src/libxl/libxl_capabilities.c
>>> +++ b/src/libxl/libxl_capabilities.c
>>> @@ -45,11 +45,16 @@ VIR_LOG_INIT("libxl.libxl_capabilities");
>>> /* see xen-unstable.hg/xen/include/asm-x86/cpufeature.h */
>>> #define LIBXL_X86_FEATURE_PAE_MASK 0x40
>>>
>>> +enum machine_type {
>>> + machine_hvm,
>>> + machine_pvh,
>>> + machine_pv,
>>> +};
>>>
>>> struct guest_arch {
>>> virArch arch;
>>> int bits;
>>> - int hvm;
>>> + enum machine_type machine;
>>> int pae;
>>> int nonpae;
>>> int ia64_be;
>>> @@ -296,7 +301,7 @@ libxlCapsInitGuests(libxl_ctx *ctx, virCapsPtr caps)
>>> /* Search for existing matching (model,hvm) tuple */
>>> for (i = 0; i < nr_guest_archs; i++) {
>>> if ((guest_archs[i].arch == arch) &&
>>> - guest_archs[i].hvm == hvm)
>>> + guest_archs[i].machine == (hvm ? machine_hvm : machine_pv))
>>> break;
>>> }
>>>
>>> @@ -308,7 +313,7 @@ libxlCapsInitGuests(libxl_ctx *ctx, virCapsPtr caps)
>>> nr_guest_archs++;
>>>
>>> guest_archs[i].arch = arch;
>>> - guest_archs[i].hvm = hvm;
>>> + guest_archs[i].machine = hvm ? machine_hvm : machine_pv;
>>>
>>> /* Careful not to overwrite a previous positive
>>> setting with a negative one here - some archs
>>> @@ -320,23 +325,40 @@ libxlCapsInitGuests(libxl_ctx *ctx, virCapsPtr caps)
>>> guest_archs[i].nonpae = nonpae;
>>> if (ia64_be)
>>> guest_archs[i].ia64_be = ia64_be;
>>> +
>>> + /* On Xen >= 4.4 add PVH for each HVM guest, and do it only once */
>>> + if ((ver_info->xen_version_major > 4 ||
>>> + (ver_info->xen_version_major == 4 &&
>>> + ver_info->xen_version_minor >= 4)) &&
>>> + hvm && i == nr_guest_archs-1) {
>>> + i = nr_guest_archs;
>>> + /* Too many arch flavours - highly unlikely ! */
>>> + if (i >= ARRAY_CARDINALITY(guest_archs))
>>> + continue;
>>> + nr_guest_archs++;
>>> + guest_archs[i].arch = arch;
>>> + guest_archs[i].machine = machine_pvh;
>>> + }
>>> }
>>> }
>>> regfree(®ex);
>>>
>>> for (i = 0; i < nr_guest_archs; ++i) {
>>> virCapsGuestPtr guest;
>>> - char const *const xen_machines[] = {guest_archs[i].hvm ? "xenfv" : "xenpv"};
>>> + char const *const xen_machines[] = {
>>> + guest_archs[i].machine == machine_hvm ? "xenfv" :
>>> + (guest_archs[i].machine == machine_pvh ? "xenpvh" : "xenpv")};
>>> virCapsGuestMachinePtr *machines;
>>>
>>> if ((machines = virCapabilitiesAllocMachines(xen_machines, 1)) == NULL)
>>> return -1;
>>>
>>> if ((guest = virCapabilitiesAddGuest(caps,
>>> - guest_archs[i].hvm ? VIR_DOMAIN_OSTYPE_HVM : VIR_DOMAIN_OSTYPE_XEN,
>>> + guest_archs[i].machine == machine_hvm ?
>>> + VIR_DOMAIN_OSTYPE_HVM : VIR_DOMAIN_OSTYPE_XEN,
>> Is a new VIR_DOMAIN_OSTYPE_XENPVH needed?
> Not sure about this. Wouldn't that require adding `os.type ==
> VIR_DOMAIN_OSTYPE_XEN || os.type == VIR_DOMAIN_OSTYPE_XENPVH` in a lot
> of places? If actual settings are mostly the same, I don't see any
> reason for introducing such value.
As long as PVHv2/HVMlite is just another impl of an existing machine type, I agree.
>
>>> guest_archs[i].arch,
>>> LIBXL_EXECBIN_DIR "/qemu-system-i386",
>>> - (guest_archs[i].hvm ?
>>> + (guest_archs[i].machine == machine_hvm ?
>>> LIBXL_FIRMWARE_DIR "/hvmloader" :
>>> NULL),
>>> 1,
>>> @@ -375,7 +397,7 @@ libxlCapsInitGuests(libxl_ctx *ctx, virCapsPtr caps)
>>> 0) == NULL)
>>> return -1;
>>>
>>> - if (guest_archs[i].hvm) {
>>> + if (guest_archs[i].machine != machine_pv) {
>>> if (virCapabilitiesAddGuestFeature(guest,
>>> "acpi",
>>> 1,
>>> @@ -390,7 +412,7 @@ libxlCapsInitGuests(libxl_ctx *ctx, virCapsPtr caps)
>>> if (virCapabilitiesAddGuestFeature(guest,
>>> "hap",
>>> 1,
>>> - 1) == NULL)
>>> + guest_archs[i].machine == machine_hvm) == NULL)
>>> return -1;
>>> }
>>> }
>>> @@ -409,7 +431,7 @@ libxlMakeDomainOSCaps(const char *machine,
>>>
>>> os->supported = true;
>>>
>>> - if (STREQ(machine, "xenpv"))
>>> + if (STREQ(machine, "xenpv") || STREQ(machine, "xenpvh"))
>>> return 0;
>>>
>>> capsLoader->supported = true;
>>> diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c
>>> index 5202ca1..aa06586 100644
>>> --- a/src/libxl/libxl_conf.c
>>> +++ b/src/libxl/libxl_conf.c
>>> @@ -173,6 +173,8 @@ libxlMakeDomCreateInfo(libxl_ctx *ctx,
>>> }
>>> } else {
>>> c_info->type = LIBXL_DOMAIN_TYPE_PV;
>>> + if (STREQ(def->os.machine, "xenpvh"))
>>> + libxl_defbool_set(&c_info->pvh, true);
>> I assume this won't change with HVMlite, aka pvh2?
> It will, unfortunately. HVMlite is enabled by setting device model to
> none.
>
>>> }
>>>
>>> if (VIR_STRDUP(c_info->name, def->name) < 0)
>>> diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c
>>> index 4957072..fa58346 100644
>>> --- a/src/libxl/libxl_driver.c
>>> +++ b/src/libxl/libxl_driver.c
>>> @@ -6321,9 +6321,11 @@ libxlConnectGetDomainCapabilities(virConnectPtr conn,
>>> emulatorbin = "/usr/bin/qemu-system-x86_64";
>>>
>>> if (machine) {
>>> - if (STRNEQ(machine, "xenpv") && STRNEQ(machine, "xenfv")) {
>>> + if (STRNEQ(machine, "xenpv") &&
>>> + STRNEQ(machine, "xenpvh") &&
>>> + STRNEQ(machine, "xenfv")) {
>>> virReportError(VIR_ERR_INVALID_ARG, "%s",
>>> - _("Xen only supports 'xenpv' and 'xenfv' machines"));
>>> + _("Xen only supports 'xenpv', 'xenpvh' and 'xenfv' machines"));
>>> goto cleanup;
>>> }
>>> } else {
>> WRT domain capabilities, should pvh be treated like pv? I.e. do they both have
>> the same max vcpus, etc?
> Yes, PVH behave like PV. But PVHv2 like HVM.
Ok, that matches my understanding of PVHv2. It is an alternative HVM impl.
Regards,
Jim
>
>> Also, supporting a new knob in the XML usually means supporting conversion of
>> that knob to xl.cfg. Can you add domXML <-> xl.cfg conversion for pvh? And a
>> test case for the conversion too please?
> I'll add this for PVHv2...
>
> [1] http://markmail.org/message/c7o7qsc3chkigdzv
>
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