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Smith" , Christian Lindig , David Scott , xen-devel@lists.xenproject.org References: <20250610225737.469690-1-jason.andryuk@amd.com> <0defc4e7-382b-4651-8255-652da17a2129@suse.com> <4b0b7554-e22f-4ef2-9236-bcc2079842d2@amd.com> Content-Language: en-US From: Jan Beulich Autocrypt: addr=jbeulich@suse.com; keydata= xsDiBFk3nEQRBADAEaSw6zC/EJkiwGPXbWtPxl2xCdSoeepS07jW8UgcHNurfHvUzogEq5xk hu507c3BarVjyWCJOylMNR98Yd8VqD9UfmX0Hb8/BrA+Hl6/DB/eqGptrf4BSRwcZQM32aZK 7Pj2XbGWIUrZrd70x1eAP9QE3P79Y2oLrsCgbZJfEwCgvz9JjGmQqQkRiTVzlZVCJYcyGGsD /0tbFCzD2h20ahe8rC1gbb3K3qk+LpBtvjBu1RY9drYk0NymiGbJWZgab6t1jM7sk2vuf0Py O9Hf9XBmK0uE9IgMaiCpc32XV9oASz6UJebwkX+zF2jG5I1BfnO9g7KlotcA/v5ClMjgo6Gl MDY4HxoSRu3i1cqqSDtVlt+AOVBJBACrZcnHAUSuCXBPy0jOlBhxPqRWv6ND4c9PH1xjQ3NP nxJuMBS8rnNg22uyfAgmBKNLpLgAGVRMZGaGoJObGf72s6TeIqKJo/LtggAS9qAUiuKVnygo 3wjfkS9A3DRO+SpU7JqWdsveeIQyeyEJ/8PTowmSQLakF+3fote9ybzd880fSmFuIEJldWxp Y2ggPGpiZXVsaWNoQHN1c2UuY29tPsJgBBMRAgAgBQJZN5xEAhsDBgsJCAcDAgQVAggDBBYC AwECHgECF4AACgkQoDSui/t3IH4J+wCfQ5jHdEjCRHj23O/5ttg9r9OIruwAn3103WUITZee e7Sbg12UgcQ5lv7SzsFNBFk3nEQQCACCuTjCjFOUdi5Nm244F+78kLghRcin/awv+IrTcIWF hUpSs1Y91iQQ7KItirz5uwCPlwejSJDQJLIS+QtJHaXDXeV6NI0Uef1hP20+y8qydDiVkv6l IreXjTb7DvksRgJNvCkWtYnlS3mYvQ9NzS9PhyALWbXnH6sIJd2O9lKS1Mrfq+y0IXCP10eS FFGg+Av3IQeFatkJAyju0PPthyTqxSI4lZYuJVPknzgaeuJv/2NccrPvmeDg6Coe7ZIeQ8Yj t0ARxu2xytAkkLCel1Lz1WLmwLstV30g80nkgZf/wr+/BXJW/oIvRlonUkxv+IbBM3dX2OV8 AmRv1ySWPTP7AAMFB/9PQK/VtlNUJvg8GXj9ootzrteGfVZVVT4XBJkfwBcpC/XcPzldjv+3 HYudvpdNK3lLujXeA5fLOH+Z/G9WBc5pFVSMocI71I8bT8lIAzreg0WvkWg5V2WZsUMlnDL9 mpwIGFhlbM3gfDMs7MPMu8YQRFVdUvtSpaAs8OFfGQ0ia3LGZcjA6Ik2+xcqscEJzNH+qh8V m5jjp28yZgaqTaRbg3M/+MTbMpicpZuqF4rnB0AQD12/3BNWDR6bmh+EkYSMcEIpQmBM51qM EKYTQGybRCjpnKHGOxG0rfFY1085mBDZCH5Kx0cl0HVJuQKC+dV2ZY5AqjcKwAxpE75MLFkr wkkEGBECAAkFAlk3nEQCGwwACgkQoDSui/t3IH7nnwCfcJWUDUFKdCsBH/E5d+0ZnMQi+G0A nAuWpQkjM1ASeQwSHEeAWPgskBQL In-Reply-To: <4b0b7554-e22f-4ef2-9236-bcc2079842d2@amd.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 11.06.2025 07:08, Jason Andryuk wrote: > On 2025-06-11 09:28, Jan Beulich wrote: >> On 11.06.2025 00:57, Jason Andryuk wrote: >>> Theses are the broad changes needed for a split hardware / control >>> domain. >>> >>> An earlier posting gave device_model privileges to hardware domain. For >>> this posting, it was split out into a new capability. This way the >>> operator can choose where to run the device models without making the >>> hardware domain have the permissions. >>> >>> The first patch add XSM_HW_PRIV for the hardware hypercalls. Unlike the >>> first posting, the control domain can call these hypercalls even though >>> it doesn't really make sense. The idea was to keep the control domain >>> all powerful from an XSM perspective. >>> >>> SILO is changed to allow control, hardwware or xenstore to service >>> domUs. Xenstore and hardware will use grants for PV interfaces. >>> Control wouldn't typically provide PV interfaces to domUs, but it is >>> given the permision to do so. Again, to keep control all powerful. >>> >>> xsm/dummy: Allow hwdom SYSCTL_readconsole/physinfo this is not strictly >>> needed. xenconsoled could read Xen's dmesg. If it's in hwdom, then >>> that permission would be required. SYSCTL_physinfo is mainly to silence >>> xl messages, which are mostly cosmetic. >>> >>> Jason Andryuk (4): >>> xen/xsm: Add XSM_HW_PRIV >>> xsm/silo: Support hwdom/control domains >>> xen: Add DOMAIN_CAPS_DEVICE_MODEL & XEN_DOMCTL_CDF_device_model >>> xsm/dummy: Allow hwdom SYSCTL_readconsole/physinfo >> >> Overall I can't help the impression that this level of disaggregation simply >> requires the use of Flask. > > I have thought about that. The problem with Flask is the complexity of > the security server. We don't want to have to deal with all that code. > A fixed policy is easier for our coverage testing. > > Exposing separate control, hardware and xenstore capabilities, it makes > sense for the default policy to function with them. Yet as indicated in replies to individual patches - the boundaries between the three aren't clear, which imo goes (to some degree at least) against the purpose of "disaggregation". Jan > This would be a > coarse level of functionality, and Flask would remain for fine-grain and > MAC enforcement. > > Regards, > Jason