[PATCH 0/2] x86: PV shim vs grant table

[PATCH 0/2] x86: PV shim vs grant table

[Jan Beulich]

While Andrew reported a randconfig build failure, I started wondering
why we'd ever build in a way different from what had failed to build.
Fix the build and then switch the shim config file accordingly.

1: fix build of PV shim when !GRANT_TABLE
2: PV shim doesn't need GRANT_TABLE

Jan

[PATCH 1/2] x86: fix build of PV shim when !GRANT_TABLE

[Jan Beulich]

To do its compat translation, shim code needs to include the compat
header. For this to work, this header first of all needs to be
generated.

Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/include/Makefile
+++ b/xen/include/Makefile
@@ -24,6 +24,7 @@ headers-$(CONFIG_X86)     += compat/arch
 headers-$(CONFIG_ARGO)    += compat/argo.h
 headers-$(CONFIG_PV)      += compat/callback.h
 headers-$(CONFIG_GRANT_TABLE) += compat/grant_table.h
+headers-$(CONFIG_PV_SHIM) += compat/grant_table.h
 headers-$(CONFIG_HVM)     += compat/hvm/dm_op.h
 headers-$(CONFIG_HVM)     += compat/hvm/hvm_op.h
 headers-$(CONFIG_HVM)     += compat/hvm/hvm_vcpu.h

[PATCH 2/2] x86: PV shim doesn't need GRANT_TABLE

[Jan Beulich]

The only reference into the code controlled by this option is from the
hypercall table, and that hypercall table entry gets overwritten.

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/arch/x86/configs/pvshim_defconfig
+++ b/xen/arch/x86/configs/pvshim_defconfig
@@ -9,6 +9,7 @@ CONFIG_EXPERT=y
 CONFIG_SCHED_NULL=y
 # Disable features not used by the PV shim
 # CONFIG_XEN_SHSTK is not set
+# CONFIG_GRANT_TABLE is not set
 # CONFIG_HYPFS is not set
 # CONFIG_BIGMEM is not set
 # CONFIG_KEXEC is not set

Re: [PATCH 1/2] x86: fix build of PV shim when !GRANT_TABLE

[Andrew Cooper]

On 29/10/2020 17:09, Jan Beulich wrote:
> To do its compat translation, shim code needs to include the compat
> header. For this to work, this header first of all needs to be
> generated.
>
> Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>

Re: [PATCH 2/2] x86: PV shim doesn't need GRANT_TABLE

[Andrew Cooper]

On 29/10/2020 17:10, Jan Beulich wrote:
> The only reference into the code controlled by this option is from the
> hypercall table, and that hypercall table entry gets overwritten.
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>