Xen doesn't care (and indeed, cannot feasibly tell) whether a hypercall was
initiated using the hypercall page or not.
For SEV-SNP/TDX encrypted VMs, use of a hypercall page would violate the
integrity properties wanted.
Explicitly state that the hypercall page is optional.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
The x86 hypercall ABI really used to have 6-argument hypercalls. V4V, the
downstream predecessor to Argo did take 6th args.
However, the 6th arg being %ebp in the 32bit ABI makes it unusable in
practice, because that's the frame pointer in builds with frame pointers
enabled. Therefore Argo was altered to being a 5-arg hypercall when it was
upstreamed.
c/s 2f531c122e ("x86: limit number of hypercall parameters to 5") removed
the ability for hypercalls to take 6 arguments.
Update the documentation to match reality.
Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
Creative Commons is a more common license than GPL for documentation purposes.
Switch to using CC-BY-4.0 to explicitly permit re-purposing and remixing of
the content.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Lars Kurth <lars.kurth@citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
Sphinx, its linters, and RST modes in common editors, expect 3 spaces of
indentation. Some bits already conform to this expectation. Update the
rest to match.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Lars Kurth <lars.kurth@citrix.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
Andrew Cooper