[RFC PATCH 16/16] HACK: Add sev_console hypercall

["Teddy Astie" <teddy.astie@xxxxxxxxxx>]

Introduce a basic console hypercall for debugging needs under SEV
when PV console is not usable at this point. This is later on used
by the earlyprintk of the experimental SEV Linux branch.

Signed-off-by: Teddy Astie <teddy.astie@xxxxxxxxxx>
---
 xen/common/coco.c            | 6 ++++++
 xen/include/hypercall-defs.c | 2 ++
 xen/include/public/xen.h     | 1 +
 3 files changed, 9 insertions(+)

diff --git a/xen/common/coco.c b/xen/common/coco.c
index d9bd17628d..23c0da6281 100644
--- a/xen/common/coco.c
+++ b/xen/common/coco.c
@@ -131,4 +131,10 @@ long do_coco_op(unsigned int cmd, 
XEN_GUEST_HANDLE_PARAM(void) arg)
     }
 }
 
+long do_sev_console_op(unsigned long c)
+{
+    printk("%c", (unsigned char)c);
+    return 0;
+}
+
 __initcall(coco_init);
\ No newline at end of file
diff --git a/xen/include/hypercall-defs.c b/xen/include/hypercall-defs.c
index 6c01a9e395..19f40f0b38 100644
--- a/xen/include/hypercall-defs.c
+++ b/xen/include/hypercall-defs.c
@@ -210,6 +210,7 @@ hypfs_op(unsigned int cmd, const char *arg1, unsigned long 
arg2, void *arg3, uns
 xenpmu_op(unsigned int op, xen_pmu_params_t *arg)
 #endif
 coco_op(unsigned int cmd, void *arg)
+sev_console_op(unsigned long c)
 
 #ifdef CONFIG_PV
 caller: pv64
@@ -297,5 +298,6 @@ mca                                do       do       -      
  -        -
 paging_domctl_cont                 do       do       do       do       -
 #endif
 coco_op                            do       do       do       do       do
+sev_console_op                     do       do       do       do       -
 
 #endif /* !CPPCHECK */
diff --git a/xen/include/public/xen.h b/xen/include/public/xen.h
index e656d6f617..04fc891353 100644
--- a/xen/include/public/xen.h
+++ b/xen/include/public/xen.h
@@ -119,6 +119,7 @@ DEFINE_XEN_GUEST_HANDLE(xen_ulong_t);
 #define __HYPERVISOR_dm_op                41
 #define __HYPERVISOR_hypfs_op             42
 #define __HYPERVISOR_coco_op              43
+#define __HYPERVISOR_sev_console_op       45
 
 /* Architecture-specific hypercall definitions. */
 #define __HYPERVISOR_arch_0               48
-- 
2.49.0



Teddy Astie | Vates XCP-ng Developer

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