[PATCH] x86/shadow: fix build without PV or HVM

[Roger Pau Monne <roger.pau@xxxxxxxxxx>]

When trying to build an hypervisor without PV or HVM (ie: using
automation/configs/x86/no_hvm_pv_config) it fails to link with:

prelink.o: In function `sh_remove_write_access_from_sl1p':
arch/x86/mm/shadow/common.c:(.text+0x72b4c): undefined reference to 
`sh_rm_write_access_from_sl1p__guest_4'
arch/x86/mm/shadow/common.c:(.text+0x72b4c): relocation truncated to fit: 
R_X86_64_PC32 against undefined symbol `sh_rm_write_access_from_sl1p__guest_4'
prelink.o: In function `sh_remove_shadow_via_pointer':
arch/x86/mm/shadow/common.c:(.text+0x72bfa): undefined reference to 
`sh_clear_shadow_entry__guest_4'
arch/x86/mm/shadow/common.c:(.text+0x72bfa): relocation truncated to fit: 
R_X86_64_PC32 against undefined symbol `sh_clear_shadow_entry__guest_4'
prelink.o: In function `_sh_resync':
arch/x86/mm/shadow/common.c:(.text+0x72e4a): undefined reference to 
`sh_resync_l1__guest_4'
arch/x86/mm/shadow/common.c:(.text+0x72e4a): relocation truncated to fit: 
R_X86_64_PC32 against undefined symbol `sh_resync_l1__guest_4'
prelink.o: In function `shadow_vcpu_init':
(.text+0x72eeb): undefined reference to `sh_paging_mode__guest_4'
prelink.o: In function `shadow_vcpu_init':
(.text+0x72eeb): relocation truncated to fit: R_X86_64_PC32 against undefined 
symbol `sh_paging_mode__guest_4'
prelink.o: In function `sh_resync_all':
(.text+0x73315): undefined reference to `sh_safe_not_to_sync__guest_4'
prelink.o: In function `sh_resync_all':
(.text+0x73315): relocation truncated to fit: R_X86_64_PC32 against undefined 
symbol `sh_safe_not_to_sync__guest_4'
prelink.o: In function `sh_resync_all':
(.text+0x7336a): undefined reference to `sh_resync_l1__guest_4'
prelink.o: In function `sh_resync_all':
(.text+0x7336a): relocation truncated to fit: R_X86_64_PC32 against undefined 
symbol `sh_resync_l1__guest_4'
prelink.o: In function `sh_validate_guest_entry':
(.text+0x736bd): undefined reference to `sh_map_and_validate_gl4e__guest_4'
prelink.o: In function `sh_validate_guest_entry':
(.text+0x736bd): relocation truncated to fit: R_X86_64_PC32 against undefined 
symbol `sh_map_and_validate_gl4e__guest_4'
prelink.o: In function `sh_validate_guest_entry':
(.text+0x736dd): undefined reference to `sh_map_and_validate_gl1e__guest_4'
prelink.o: In function `sh_validate_guest_entry':
(.text+0x736dd): relocation truncated to fit: R_X86_64_PC32 against undefined 
symbol `sh_map_and_validate_gl1e__guest_4'
prelink.o: In function `sh_validate_guest_entry':
(.text+0x736fd): undefined reference to `sh_map_and_validate_gl2e__guest_4'
prelink.o: In function `sh_validate_guest_entry':
(.text+0x736fd): relocation truncated to fit: R_X86_64_PC32 against undefined 
symbol `sh_map_and_validate_gl2e__guest_4'
prelink.o: In function `sh_validate_guest_entry':
(.text+0x7371d): undefined reference to `sh_map_and_validate_gl2he__guest_4'
prelink.o: In function `sh_validate_guest_entry':
(.text+0x7371d): relocation truncated to fit: R_X86_64_PC32 against undefined 
symbol `sh_map_and_validate_gl2he__guest_4'
prelink.o: In function `sh_validate_guest_entry':
(.text+0x7373d): undefined reference to `sh_map_and_validate_gl3e__guest_4'
prelink.o: In function `sh_validate_guest_entry':
(.text+0x7373d): additional relocation overflows omitted from the output
prelink.o: In function `shadow_unhook_mappings':
(.text+0x7379b): undefined reference to `sh_unhook_64b_mappings__guest_4'
prelink.o: In function `sh_destroy_shadow':
(.text+0x74183): undefined reference to `sh_destroy_l1_shadow__guest_4'
prelink.o: In function `sh_destroy_shadow':
(.text+0x74199): undefined reference to `sh_destroy_l4_shadow__guest_4'
prelink.o: In function `sh_destroy_shadow':
(.text+0x741a1): undefined reference to `sh_destroy_l3_shadow__guest_4'
prelink.o: In function `sh_destroy_shadow':
(.text+0x741a9): undefined reference to `sh_destroy_l2_shadow__guest_4'
prelink.o:(.data.rel.ro.local+0x1018): undefined reference to 
`sh_remove_l1_shadow__guest_4'
prelink.o:(.data.rel.ro.local+0x1020): undefined reference to 
`sh_remove_l1_shadow__guest_4'
prelink.o:(.data.rel.ro.local+0x1028): undefined reference to 
`sh_remove_l2_shadow__guest_4'
prelink.o:(.data.rel.ro.local+0x1030): undefined reference to 
`sh_remove_l3_shadow__guest_4'
prelink.o:(.data.rel.ro.local+0x1068): undefined reference to 
`sh_rm_mappings_from_l1__guest_4'
prelink.o:(.data.rel.ro.local+0x1070): undefined reference to 
`sh_rm_mappings_from_l1__guest_4'
ld: /root/src/xen/xen/.xen-syms.0: hidden symbol 
`sh_destroy_l2_shadow__guest_4' isn't defined
ld: final link failed: Bad value

Fix this by making shadow depend on either PV or HVM being selected in
Kconfig.

Fixes: aff8bf94ce6 ('x86/shadow: only 4-level guest code needs building when 
!HVM')
Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
 xen/arch/x86/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/xen/arch/x86/Kconfig b/xen/arch/x86/Kconfig
index 32b9f23a20e..966b3634591 100644
--- a/xen/arch/x86/Kconfig
+++ b/xen/arch/x86/Kconfig
@@ -121,6 +121,7 @@ config XEN_SHSTK
 
 config SHADOW_PAGING
        bool "Shadow Paging"
+       depends on PV || HVM
        default !PV_SHIM_EXCLUSIVE
        depends on PV || HVM
        ---help---
-- 
2.30.1