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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [RFC][PATCH 01/13] tools: introduce some new parameters to set rdm policy
Sorry for the late review.
On Fri, Apr 10, 2015 at 05:21:52PM +0800, Tiejun Chen wrote:
> This patch introduces user configurable parameters to specify RDM
> resource and according policies,
>
> Global RDM parameter:
> rdm = [ 'host, reserve=force/try' ]
> Per-device RDM parameter:
> pci = [ 'sbdf, rdm_reserve=force/try' ]
>
> Global RDM parameter allows user to specify reserved regions explicitly,
> e.g. using 'host' to include all reserved regions reported on this platform
> which is good to handle hotplug scenario. In the future this parameter
> may be further extended to allow specifying random regions, e.g. even
> those belonging to another platform as a preparation for live migration
> with passthrough devices.
>
> 'force/try' policy decides how to handle conflict when reserving RDM
> regions in pfn space. If conflict exists, 'force' means an immediate error
> so VM will be killed, while 'try' allows moving forward with a warning
> message thrown out.
>
> Default per-device RDM policy is 'force', while default global RDM policy
> is 'try'. When both policies are specified on a given region, 'force' is
> always preferred.
>
> Signed-off-by: Tiejun Chen <tiejun.chen@xxxxxxxxx>
> ---
> docs/man/xl.cfg.pod.5 | 44 +++++++++++++++++++++++++
> docs/misc/vtd.txt | 34 ++++++++++++++++++++
> tools/libxl/libxl_create.c | 5 +++
> tools/libxl/libxl_types.idl | 18 +++++++++++
> tools/libxl/libxlu_pci.c | 78
> +++++++++++++++++++++++++++++++++++++++++++++
> tools/libxl/libxlutil.h | 4 +++
> tools/libxl/xl_cmdimpl.c | 21 +++++++++++-
> 7 files changed, 203 insertions(+), 1 deletion(-)
>
> diff --git a/docs/man/xl.cfg.pod.5 b/docs/man/xl.cfg.pod.5
> index 408653f..9ed3055 100644
> --- a/docs/man/xl.cfg.pod.5
> +++ b/docs/man/xl.cfg.pod.5
> @@ -583,6 +583,36 @@ assigned slave device.
>
> =back
>
> +=item B<rdm=[ "TYPE", "RDM_RESERVE_STRING", ... ]>
> +
Shouldn't this be "TYPE,RDM_RESERVE_STRIGN" according to your commit
message? If the only available config is just one string, you probably
don't need a list for this?
> +(HVM/x86 only) Specifies the information about Reserved Device Memory (RDM),
> +which is necessary to enable robust device passthrough usage. One example of
> +RDM is reported through ACPI Reserved Memory Region Reporting (RMRR)
> +structure on x86 platform.
> +Each B<RDM_CHECK_STRING> has the form C<["TYPE",KEY=VALUE,KEY=VALUE,...>
> where:
> +
RDM_CHECK_STRING?
> +=over 4
> +
> +=item B<"TYPE">
> +
> +Currently we just have one type. 'host' means all reserved device memory on
> +this platform should be reserved in this VM's pfn space.
> +
What are other possible types? If there is only one type then we can
simply ignore the type?
> +=item B<KEY=VALUE>
> +
> +Possible B<KEY>s are:
> +
> +=over 4
> +
> +=item B<reserve="STRING">
> +
> +Conflict may be detected when reserving reserved device memory in gfn space.
> +'force' means an unsolved conflict leads to immediate VM destroy, while
Do you mean "immediate VM crash"?
> +'try' allows VM moving forward with a warning message thrown out. 'try'
> +is default.
Can you please your double quotes for "force", "try" etc.
> +
> +Note this may be overrided by another sub item, rdm_reserve, in pci device.
> +
> =item B<pci=[ "PCI_SPEC_STRING", "PCI_SPEC_STRING", ... ]>
>
> Specifies the host PCI devices to passthrough to this guest. Each
> B<PCI_SPEC_STRING>
> @@ -645,6 +675,20 @@ dom0 without confirmation. Please use with care.
> D0-D3hot power management states for the PCI device. False (0) by
> default.
>
> +=item B<rdm_check="STRING">
> +
> +(HVM/x86 only) Specifies the information about Reserved Device Memory (RDM),
> +which is necessary to enable robust device passthrough usage. One example of
> +RDM is reported through ACPI Reserved Memory Region Reporting (RMRR)
> +structure on x86 platform.
> +
> +Conflict may be detected when reserving reserved device memory in gfn space.
> +'force' means an unsolved conflict leads to immediate VM destroy, while
> +'try' allows VM moving forward with a warning message thrown out. 'force'
> +is default.
> +
> +Note this would override another global item, rdm = [''].
> +
Note this would override global B<rdm> option.
> =back
>
> =back
> diff --git a/docs/misc/vtd.txt b/docs/misc/vtd.txt
> index 9af0e99..d7434d6 100644
> --- a/docs/misc/vtd.txt
> +++ b/docs/misc/vtd.txt
> @@ -111,6 +111,40 @@ in the config file:
> To override for a specific device:
> pci = [ '01:00.0,msitranslate=0', '03:00.0' ]
>
> +RDM, 'reserved device memory', for PCI Device Passthrough
> +---------------------------------------------------------
> +
> +There are some devices the BIOS controls, for e.g. USB devices to perform
> +PS2 emulation. The regions of memory used for these devices are marked
> +reserved in the e820 map. When we turn on DMA translation, DMA to those
> +regions will fail. Hence BIOS uses RMRR to specify these regions along with
> +devices that need to access these regions. OS is expected to setup
> +identity mappings for these regions for these devices to access these
> regions.
> +
> +While creating a VM we should reserve them in advance, and avoid any
> conflicts.
> +So we introduce user configurable parameters to specify RDM resource and
> +according policies,
> +
> +To enable this globally, add "rdm" in the config file:
> +
> + rdm = [ 'host, reserve=force/try' ]
> +
The "force/try" should be called "policy". And then you explain what
policies we have.
> +Or just for a specific device:
> +
> + pci = [ '01:00.0,rdm_reserve=force/try', '03:00.0' ]
> +
> +Global RDM parameter allows user to specify reserved regions explicitly.
> +Using 'host' to include all reserved regions reported on this platform
> +which is good to handle hotplug scenario. In the future this parameter
> +may be further extended to allow specifying random regions, e.g. even
> +those belonging to another platform as a preparation for live migration
> +with passthrough devices.
> +
> +'force/try' policy decides how to handle conflict when reserving RDM
> +regions in pfn space. If conflict exists, 'force' means an immediate error
> +so VM will be killed, while 'try' allows moving forward with a warning
Be killed by whom? I think it's hvmloader crashes voluntarily, right?
> +message thrown out.
> +
>
> Caveat on Conventional PCI Device Passthrough
> ---------------------------------------------
> diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
> index 98687bd..9ed40d4 100644
> --- a/tools/libxl/libxl_create.c
> +++ b/tools/libxl/libxl_create.c
> @@ -1407,6 +1407,11 @@ static void domcreate_attach_pci(libxl__egc *egc,
> libxl__multidev *multidev,
> }
>
> for (i = 0; i < d_config->num_pcidevs; i++) {
> + /*
> + * If the rdm global policy is 'force' we should override each
> device.
> + */
> + if (d_config->b_info.rdm.reserve == LIBXL_RDM_RESERVE_FLAG_FORCE)
> + d_config->pcidevs[i].rdm_reserve = LIBXL_RDM_RESERVE_FLAG_FORCE;
> ret = libxl__device_pci_add(gc, domid, &d_config->pcidevs[i], 1);
> if (ret < 0) {
> LIBXL__LOG(ctx, LIBXL__LOG_ERROR,
> diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
> index 47af340..5786455 100644
> --- a/tools/libxl/libxl_types.idl
> +++ b/tools/libxl/libxl_types.idl
> @@ -71,6 +71,17 @@ libxl_domain_type = Enumeration("domain_type", [
> (2, "PV"),
> ], init_val = "LIBXL_DOMAIN_TYPE_INVALID")
>
> +libxl_rdm_reserve_type = Enumeration("rdm_reserve_type", [
> + (0, "none"),
> + (1, "host"),
> + ])
> +
> +libxl_rdm_reserve_flag = Enumeration("rdm_reserve_flag", [
> + (-1, "invalid"),
> + (0, "force"),
> + (1, "try"),
> + ])
If you don't set init_val, the default value would be "force" (0), is this
want you want?
> +
> libxl_channel_connection = Enumeration("channel_connection", [
> (0, "UNKNOWN"),
> (1, "PTY"),
> @@ -356,6 +367,11 @@ libxl_domain_sched_params =
> Struct("domain_sched_params",[
> ("budget", integer, {'init_val':
> 'LIBXL_DOMAIN_SCHED_PARAM_BUDGET_DEFAULT'}),
> ])
>
> +libxl_rdm_reserve = Struct("rdm_reserve", [
> + ("type", libxl_rdm_reserve_type),
> + ("reserve", libxl_rdm_reserve_flag),
> + ])
> +
> libxl_domain_build_info = Struct("domain_build_info",[
> ("max_vcpus", integer),
> ("avail_vcpus", libxl_bitmap),
> @@ -401,6 +417,7 @@ libxl_domain_build_info = Struct("domain_build_info",[
> ("kernel", string),
> ("cmdline", string),
> ("ramdisk", string),
> + ("rdm", libxl_rdm_reserve),
> ("u", KeyedUnion(None, libxl_domain_type, "type",
> [("hvm", Struct(None, [("firmware", string),
> ("bios", libxl_bios_type),
> @@ -521,6 +538,7 @@ libxl_device_pci = Struct("device_pci", [
> ("power_mgmt", bool),
> ("permissive", bool),
> ("seize", bool),
> + ("rdm_reserve", libxl_rdm_reserve_flag),
> ])
>
> libxl_device_vtpm = Struct("device_vtpm", [
> diff --git a/tools/libxl/libxlu_pci.c b/tools/libxl/libxlu_pci.c
> index 26fb143..45be0d9 100644
> --- a/tools/libxl/libxlu_pci.c
> +++ b/tools/libxl/libxlu_pci.c
> @@ -42,6 +42,8 @@ static int pcidev_struct_fill(libxl_device_pci *pcidev,
> unsigned int domain,
> #define STATE_OPTIONS_K 6
> #define STATE_OPTIONS_V 7
> #define STATE_TERMINAL 8
> +#define STATE_TYPE 9
> +#define STATE_CHECK_FLAG 10
> int xlu_pci_parse_bdf(XLU_Config *cfg, libxl_device_pci *pcidev, const char
> *str)
> {
> unsigned state = STATE_DOMAIN;
> @@ -143,6 +145,17 @@ int xlu_pci_parse_bdf(XLU_Config *cfg, libxl_device_pci
> *pcidev, const char *str
> pcidev->permissive = atoi(tok);
> }else if ( !strcmp(optkey, "seize") ) {
> pcidev->seize = atoi(tok);
> + }else if ( !strcmp(optkey, "rdm_reserve") ) {
> + if ( !strcmp(tok, "force") ) {
> + pcidev->rdm_reserve = LIBXL_RDM_RESERVE_FLAG_FORCE;
> + } else if ( !strcmp(tok, "try") ) {
> + pcidev->rdm_reserve = LIBXL_RDM_RESERVE_FLAG_TRY;
> + } else {
> + pcidev->rdm_reserve = LIBXL_RDM_RESERVE_FLAG_FORCE;
> + XLU__PCI_ERR(cfg, "Unknown PCI RDM property flag
> value:"
> + " %s, so goes 'force' by default.",
If this is not an error, you don't need XLU__PCI_ERR.
But I would say we should just treat this as an error and
abort/exit/report (whatever the parser should do in this case).
> + tok);
> + }
> }else{
> XLU__PCI_ERR(cfg, "Unknown PCI BDF option: %s", optkey);
> }
> @@ -167,6 +180,71 @@ parse_error:
> return ERROR_INVAL;
> }
>
> +int xlu_rdm_parse(XLU_Config *cfg, libxl_rdm_reserve *rdm, const char *str)
> +{
> + unsigned state = STATE_TYPE;
> + char *buf2, *tok, *ptr, *end;
> +
> + if ( NULL == (buf2 = ptr = strdup(str)) )
> + return ERROR_NOMEM;
> +
> + for(tok = ptr, end = ptr + strlen(ptr) + 1; ptr < end; ptr++) {
> + switch(state) {
> + case STATE_TYPE:
> + if ( *ptr == '\0' || *ptr == ',' ) {
> + state = STATE_CHECK_FLAG;
> + *ptr = '\0';
> + if ( !strcmp(tok, "host") ) {
> + rdm->type = LIBXL_RDM_RESERVE_TYPE_HOST;
> + } else {
> + XLU__PCI_ERR(cfg, "Unknown RDM state option: %s", tok);
> + goto parse_error;
> + }
> + tok = ptr + 1;
> + }
> + break;
> + case STATE_CHECK_FLAG:
> + if ( *ptr == '=' ) {
> + state = STATE_OPTIONS_V;
> + *ptr = '\0';
> + if ( strcmp(tok, "reserve") ) {
> + XLU__PCI_ERR(cfg, "Unknown RDM property value: %s", tok);
> + goto parse_error;
> + }
> + tok = ptr + 1;
> + }
> + break;
> + case STATE_OPTIONS_V:
> + if ( *ptr == ',' || *ptr == '\0' ) {
> + state = STATE_TERMINAL;
> + *ptr = '\0';
> + if ( !strcmp(tok, "force") ) {
> + rdm->reserve = LIBXL_RDM_RESERVE_FLAG_FORCE;
> + } else if ( !strcmp(tok, "try") ) {
> + rdm->reserve = LIBXL_RDM_RESERVE_FLAG_TRY;
> + } else {
> + XLU__PCI_ERR(cfg, "Unknown RDM property flag value: %s",
> + tok);
> + goto parse_error;
> + }
> + tok = ptr + 1;
> + }
> + default:
> + break;
> + }
> + }
> +
> + free(buf2);
> +
> + if ( tok != ptr || state != STATE_TERMINAL )
> + goto parse_error;
> +
> + return 0;
> +
> +parse_error:
> + return ERROR_INVAL;
> +}
> +
> /*
> * Local variables:
> * mode: C
> diff --git a/tools/libxl/libxlutil.h b/tools/libxl/libxlutil.h
> index 0333e55..80497f8 100644
> --- a/tools/libxl/libxlutil.h
> +++ b/tools/libxl/libxlutil.h
> @@ -93,6 +93,10 @@ int xlu_disk_parse(XLU_Config *cfg, int nspecs, const char
> *const *specs,
> */
> int xlu_pci_parse_bdf(XLU_Config *cfg, libxl_device_pci *pcidev, const char
> *str);
>
> +/*
> + * RDM parsing
> + */
> +int xlu_rdm_parse(XLU_Config *cfg, libxl_rdm_reserve *rdm, const char *str);
>
> /*
> * Vif rate parsing.
> diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
> index 04faf98..9a58464 100644
> --- a/tools/libxl/xl_cmdimpl.c
> +++ b/tools/libxl/xl_cmdimpl.c
> @@ -988,7 +988,7 @@ static void parse_config_data(const char *config_source,
> const char *buf;
> long l;
> XLU_Config *config;
> - XLU_ConfigList *cpus, *vbds, *nics, *pcis, *cvfbs, *cpuids, *vtpms;
> + XLU_ConfigList *cpus, *vbds, *nics, *pcis, *cvfbs, *cpuids, *vtpms,
> *rdms;
> XLU_ConfigList *channels, *ioports, *irqs, *iomem, *viridian;
> int num_ioports, num_irqs, num_iomem, num_cpus, num_viridian;
> int pci_power_mgmt = 0;
> @@ -1727,6 +1727,23 @@ skip_vfb:
> xlu_cfg_get_defbool(config, "e820_host", &b_info->u.pv.e820_host, 0);
> }
>
> + /*
> + * By default our global policy is to query all rdm entries, and
> + * force reserve them.
> + */
> + b_info->rdm.type = LIBXL_RDM_RESERVE_TYPE_HOST;
> + b_info->rdm.reserve = LIBXL_RDM_RESERVE_FLAG_TRY;
This should probably to into the _setdefault function of
libxl_domain_build_info.
> + if (!xlu_cfg_get_list (config, "rdm", &rdms, 0, 0)) {
> + if ((buf = xlu_cfg_get_listitem (rdms, 0)) != NULL ) {
> + libxl_rdm_reserve rdm;
> + if (!xlu_rdm_parse(config, &rdm, buf))
> + {
> + b_info->rdm.type = rdm.type;
> + b_info->rdm.reserve = rdm.reserve;
> + }
You only have one rdm in b_info, so there is no need to use a list for
it in config file.
One side note is that this patch should probably be placed later in this
series, after other patches to add the necessary underlying
functionalities.
Wei.
> + }
> + }
> +
> if (!xlu_cfg_get_list (config, "pci", &pcis, 0, 0)) {
> d_config->num_pcidevs = 0;
> d_config->pcidevs = NULL;
> @@ -1741,6 +1758,8 @@ skip_vfb:
> pcidev->power_mgmt = pci_power_mgmt;
> pcidev->permissive = pci_permissive;
> pcidev->seize = pci_seize;
> + /* We'd like to force reserve rdm specific to a device by
> default.*/
> + pcidev->rdm_reserve = LIBXL_RDM_RESERVE_FLAG_FORCE;
> if (!xlu_pci_parse_bdf(config, pcidev, buf))
> d_config->num_pcidevs++;
> }
> --
> 1.9.1
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