This enumeration controls TEE type for a domain. Currently there is two possible options: either 'none' or 'optee'.

'none' is the default value and it basically disables TEE support at all.

'optee' enables access to the OP-TEE running on a host machine. This requires special OP-TEE build with virtualization support enabled.

Signed-off-by: Volodymyr Babchuk volodymyr_babchuk@epam.com

---

Changes from v6: - Updated documentation according to Julien Grall's suggestions, add link to OP-TEE documentation

Changes from v5: - Replaced "native" with "optee" in the commit description. - Updated and extended documentation based on Julien Grall's and Ian Jackson's suggestions.

Changes from v4: - "native" option was replaced with "optee" - "tee" property was moved from arch-specific section to the global one. Documentation moved inside "Devices" section.

Changes from v3: - tee_enabled renamed to tee_type. Currently two types are supported as described in the commit message - Add LIBXL_HAVE_BUILDINFO_ARCH_ARM_TEE definition

Changes from v2: - Use arch.tee_enabled instead of separate domctl --- docs/man/xl.cfg.5.pod.in | 29 +++++++++++++++++++++++++++++ tools/libxl/libxl.h | 5 +++++ tools/libxl/libxl_arm.c | 13 +++++++++++++ tools/libxl/libxl_types.idl | 6 ++++++ tools/xl/xl_parse.c | 9 +++++++++ 5 files changed, 62 insertions(+)

diff --git a/docs/man/xl.cfg.5.pod.in b/docs/man/xl.cfg.5.pod.in index c99d40307e..e71b3b411d 100644 --- a/docs/man/xl.cfg.5.pod.in +++ b/docs/man/xl.cfg.5.pod.in @@ -1544,6 +1544,35 @@ Set maximum height for pointer device.

=back

+=item B<tee="STRING"> + +B<Arm only.> Set TEE type for the guest. TEE is a Trusted Execution +Environment -- separate secure OS found on some platforms. B<STRING> can be one of the: + +=over 4 + +=item B<none> + +"Don't allow the guest to use TEE if present on the platform. This is +the default value. + +=item B<optee> + +Allow a guest to access the host OP-TEE OS. Xen will mediate the +access to OP-TEE and the resource isolation will be provided directly +by OP-TEE. OP-TEE itself may limit the number of guests that can +concurrently use it. This requires a virtualization-aware OP-TEE for +this to work. + +You can refer to +L<OP-TEE documentation|https://optee.readthedocs.io/architecture/virtualization.html%3E +for more information about how to enable and configure virtualization support +in OP-TEE. + +This feature is a B<technology preview>. + +=back + =back

=head2 Paravirtualised (PV) Guest Specific Options diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h index 9bacfb97f0..1fe6ea2bd8 100644 --- a/tools/libxl/libxl.h +++ b/tools/libxl/libxl.h @@ -273,6 +273,11 @@ */ #define LIBXL_HAVE_BUILDINFO_ARM_GIC_VERSION 1

+/* + * libxl_domain_build_info has the arch_arm.tee field. + */ +#define LIBXL_HAVE_BUILDINFO_ARCH_ARM_TEE 1 + /* * LIBXL_HAVE_SOFT_RESET indicates that libxl supports performing * 'soft reset' for domains and there is 'soft_reset' shutdown reason diff --git a/tools/libxl/libxl_arm.c b/tools/libxl/libxl_arm.c index 141e159043..6b72c00960 100644 --- a/tools/libxl/libxl_arm.c +++ b/tools/libxl/libxl_arm.c @@ -89,6 +89,19 @@ int libxl__arch_domain_prepare_config(libxl__gc *gc, return ERROR_FAIL; }

+ switch (d_config->b_info.tee) { + case LIBXL_TEE_TYPE_NONE: + config->arch.tee_type = XEN_DOMCTL_CONFIG_TEE_NONE; + break; + case LIBXL_TEE_TYPE_OPTEE: + config->arch.tee_type = XEN_DOMCTL_CONFIG_TEE_OPTEE; + break; + default: + LOG(ERROR, "Unknown TEE type %d", + d_config->b_info.tee); + return ERROR_FAIL; + } + return 0; }

diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl index b61399ce36..fa5ee65463 100644 --- a/tools/libxl/libxl_types.idl +++ b/tools/libxl/libxl_types.idl @@ -460,6 +460,11 @@ libxl_gic_version = Enumeration("gic_version", [ (0x30, "v3") ], init_val = "LIBXL_GIC_VERSION_DEFAULT")

+libxl_tee_type = Enumeration("tee_type", [ + (0, "none"), + (1, "optee") + ], init_val = "LIBXL_TEE_TYPE_NONE") + libxl_rdm_reserve = Struct("rdm_reserve", [ ("strategy", libxl_rdm_reserve_strategy), ("policy", libxl_rdm_reserve_policy), @@ -537,6 +542,7 @@ libxl_domain_build_info = Struct("domain_build_info",[ ("nested_hvm", libxl_defbool), ("apic", libxl_defbool), ("dm_restrict", libxl_defbool), + ("tee", libxl_tee_type), ("u", KeyedUnion(None, libxl_domain_type, "type", [("hvm", Struct(None, [("firmware", string), ("bios", libxl_bios_type), diff --git a/tools/xl/xl_parse.c b/tools/xl/xl_parse.c index e105bda2bb..0604374ef3 100644 --- a/tools/xl/xl_parse.c +++ b/tools/xl/xl_parse.c @@ -2691,6 +2691,15 @@ skip_usbdev: } }

+ if (!xlu_cfg_get_string (config, "tee", &buf, 1)) { + e = libxl_tee_type_from_string(buf, &b_info->tee); + if (e) { + fprintf(stderr, + "Unknown tee "%s" specified\n", buf); + exit(-ERROR_FAIL); + } + } + parse_vkb_list(config, d_config);

xlu_cfg_destroy(config);

It is nicer, when options for particular TEE mediators (currently, OP-TEE only) are following generic "Enable TEE mediators support" option in the menuconfig:

[*] Enable TEE mediators support [ ] Enable OP-TEE mediator

Signed-off-by: Volodymyr Babchuk volodymyr_babchuk@epam.com --- xen/arch/arm/Kconfig | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig index 04d399ffbf..c2db2a6953 100644 --- a/xen/arch/arm/Kconfig +++ b/xen/arch/arm/Kconfig @@ -113,6 +113,8 @@ config TEE This option enables generic TEE mediators support. It allows guests to access real TEE via one of TEE mediators implemented in XEN.

+source "arch/arm/tee/Kconfig" + endmenu

menu "ARM errata workaround via the alternative framework" @@ -238,5 +240,3 @@ source "arch/arm/platforms/Kconfig" source "common/Kconfig"

source "drivers/Kconfig" - -source "arch/arm/tee/Kconfig"

Add basic information about the OP-TEE mediator and note about dependency on virtualization-aware OP-TEE.

Signed-off-by: Volodymyr Babchuk volodymyr_babchuk@epam.com --- xen/arch/arm/tee/Kconfig | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/xen/arch/arm/tee/Kconfig b/xen/arch/arm/tee/Kconfig index 5b829db2e9..b4b6aa2610 100644 --- a/xen/arch/arm/tee/Kconfig +++ b/xen/arch/arm/tee/Kconfig @@ -2,3 +2,8 @@ config OPTEE bool "Enable OP-TEE mediator" default n depends on TEE + help + Enable experimental OP-TEE mediator. It allows guests to access + OP-TEE running on your platform. This requires virtualization-enabled + OP-TEE present. You can learn more about virtualization for OP-TEE + at https://optee.readthedocs.io/architecture/virtualization.html

Hi Volodymyr,

On 6/19/19 6:54 PM, Volodymyr Babchuk wrote:

This is workaround for OP-TEE 3.5. This is the first OP-TEE release which supports virtualization, but there is no way to tell if OP-TEE was built with that support enabled. We can probe for it by calling SMC that is available only when OP-TEE is built with virtualization support.

Signed-off-by: Volodymyr Babchuk volodymyr_babchuk@epam.com

Acked-by: Julien Grall julien.grall@arm.com

Cheers,

---

xen/arch/arm/tee/optee.c | 10 ++++++++++ 1 file changed, 10 insertions(+)

diff --git a/xen/arch/arm/tee/optee.c b/xen/arch/arm/tee/optee.c index 28d34360fc..14381d6b2d 100644 --- a/xen/arch/arm/tee/optee.c +++ b/xen/arch/arm/tee/optee.c @@ -172,6 +172,16 @@ static bool optee_probe(void) return false; }

• /*

• * Workaround: OP-TEE 3.5 have no way to tell if it is build with
  

• * virtualization support. But we can probe for OPTEE_SMC_VM_DESTROYED
  

• * call. It will return OPTEE_SMC_RETURN_UNKNOWN_FUNCTION if
  

• * OP-TEE have no virtualization support enabled.
  

• */
  

• arm_smccc_smc(OPTEE_SMC_VM_DESTROYED, 0, 0, 0, 0, 0, 0, 0, &resp);
• if ( resp.a0 == OPTEE_SMC_RETURN_UNKNOWN_FUNCTION )

•    return false;
  

• return true;
  

  }

Hello Ian,

Do you have a couple of minutes to check this and the following patches?

This enumeration controls TEE type for a domain. Currently there is two possible options: either 'none' or 'optee'.

'none' is the default value and it basically disables TEE support at all.

'optee' enables access to the OP-TEE running on a host machine. This requires special OP-TEE build with virtualization support enabled.

Signed-off-by: Volodymyr Babchuk volodymyr_babchuk@epam.com

---

Changes from v6:

• Updated documentation according to Julien Grall's suggestions, add link to OP-TEE documentation

Changes from v5:

• Replaced "native" with "optee" in the commit description.
• Updated and extended documentation based on Julien Grall's and Ian Jackson's suggestions.

Changes from v4:

• "native" option was replaced with "optee"
• "tee" property was moved from arch-specific section to the global one. Documentation moved inside "Devices" section.

Changes from v3:

• tee_enabled renamed to tee_type. Currently two types are supported as described in the commit message
• Add LIBXL_HAVE_BUILDINFO_ARCH_ARM_TEE definition

Changes from v2:

• Use arch.tee_enabled instead of separate domctl

---

docs/man/xl.cfg.5.pod.in | 29 +++++++++++++++++++++++++++++ tools/libxl/libxl.h | 5 +++++ tools/libxl/libxl_arm.c | 13 +++++++++++++ tools/libxl/libxl_types.idl | 6 ++++++ tools/xl/xl_parse.c | 9 +++++++++ 5 files changed, 62 insertions(+)

diff --git a/docs/man/xl.cfg.5.pod.in b/docs/man/xl.cfg.5.pod.in index c99d40307e..e71b3b411d 100644 --- a/docs/man/xl.cfg.5.pod.in +++ b/docs/man/xl.cfg.5.pod.in @@ -1544,6 +1544,35 @@ Set maximum height for pointer device. =back +=item B<tee="STRING">

+B<Arm only.> Set TEE type for the guest. TEE is a Trusted Execution +Environment -- separate secure OS found on some platforms. B<STRING> can be one of the:

+=over 4

+=item B<none>

+"Don't allow the guest to use TEE if present on the platform. This is +the default value.

+=item B<optee>

+Allow a guest to access the host OP-TEE OS. Xen will mediate the +access to OP-TEE and the resource isolation will be provided directly +by OP-TEE. OP-TEE itself may limit the number of guests that can +concurrently use it. This requires a virtualization-aware OP-TEE for +this to work.

+You can refer to +L<OP-TEE documentation|https://optee.readthedocs.io/architecture/virtualization.html%3E +for more information about how to enable and configure virtualization support +in OP-TEE.

+This feature is a B<technology preview>.

+=back

=back =head2 Paravirtualised (PV) Guest Specific Options diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h index 9bacfb97f0..1fe6ea2bd8 100644 --- a/tools/libxl/libxl.h +++ b/tools/libxl/libxl.h @@ -273,6 +273,11 @@ */ #define LIBXL_HAVE_BUILDINFO_ARM_GIC_VERSION 1 +/*

• • libxl_domain_build_info has the arch_arm.tee field.
• */

+#define LIBXL_HAVE_BUILDINFO_ARCH_ARM_TEE 1

/*

• LIBXL_HAVE_SOFT_RESET indicates that libxl supports performing
• 'soft reset' for domains and there is 'soft_reset' shutdown reason

diff --git a/tools/libxl/libxl_arm.c b/tools/libxl/libxl_arm.c index 141e159043..6b72c00960 100644 --- a/tools/libxl/libxl_arm.c +++ b/tools/libxl/libxl_arm.c @@ -89,6 +89,19 @@ int libxl__arch_domain_prepare_config(libxl__gc *gc, return ERROR_FAIL; }

• switch (d_config->b_info.tee) {
• case LIBXL_TEE_TYPE_NONE:

•    config->arch.tee_type = XEN_DOMCTL_CONFIG_TEE_NONE;
  

•    break;
  

• case LIBXL_TEE_TYPE_OPTEE:

•    config->arch.tee_type = XEN_DOMCTL_CONFIG_TEE_OPTEE;
  

•    break;
  

• default:

•    LOG(ERROR, "Unknown TEE type %d",
  

•        d_config->b_info.tee);
  

•    return ERROR_FAIL;
  

• }
• return 0;

} diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl index b61399ce36..fa5ee65463 100644 --- a/tools/libxl/libxl_types.idl +++ b/tools/libxl/libxl_types.idl @@ -460,6 +460,11 @@ libxl_gic_version = Enumeration("gic_version", [ (0x30, "v3") ], init_val = "LIBXL_GIC_VERSION_DEFAULT") +libxl_tee_type = Enumeration("tee_type", [

• (0, "none"),
• (1, "optee")
• ], init_val = "LIBXL_TEE_TYPE_NONE")

libxl_rdm_reserve = Struct("rdm_reserve", [ ("strategy", libxl_rdm_reserve_strategy), ("policy", libxl_rdm_reserve_policy), @@ -537,6 +542,7 @@ libxl_domain_build_info = Struct("domain_build_info",[ ("nested_hvm", libxl_defbool), ("apic", libxl_defbool), ("dm_restrict", libxl_defbool),

• ("tee", libxl_tee_type), ("u", KeyedUnion(None, libxl_domain_type, "type", [("hvm", Struct(None, [("firmware", string), ("bios", libxl_bios_type),

diff --git a/tools/xl/xl_parse.c b/tools/xl/xl_parse.c index e105bda2bb..0604374ef3 100644 --- a/tools/xl/xl_parse.c +++ b/tools/xl/xl_parse.c @@ -2691,6 +2691,15 @@ skip_usbdev: } }

• if (!xlu_cfg_get_string (config, "tee", &buf, 1)) {

•    e = libxl_tee_type_from_string(buf, &b_info->tee);
  

•    if (e) {
  

•        fprintf(stderr,
  

•                "Unknown tee \"%s\" specified\n", buf);
  

•        exit(-ERROR_FAIL);
  

•    }
  

• }
• parse_vkb_list(config, d_config);

xlu_cfg_destroy(config);