[PATCH v3 0/7] Remove 32-bit Xen PV guest support

From: Juergen Gross
Date: Fri Aug 07 2020 - 04:38:35 EST


The long term plan has been to replace Xen PV guests by PVH. The first
victim of that plan are now 32-bit PV guests, as those are used only
rather seldom these days. Xen on x86 requires 64-bit support and with
Grub2 now supporting PVH officially since version 2.04 there is no
need to keep 32-bit PV guest support alive in the Linux kernel.
Additionally Meltdown mitigation is not available in the kernel running
as 32-bit PV guest, so dropping this mode makes sense from security
point of view, too.

Changes in V3:
- addressed comments to V2
- split patch 1 into 2 patches
- new patches 3 and 7

Changes in V2:
- rebase to 5.8 kernel
- addressed comments to V1
- new patches 3 and 4

Juergen Gross (7):
x86/xen: remove 32-bit Xen PV guest support
x86/xen: eliminate xen-asm_64.S
x86/xen: drop tests for highmem in pv code
x86/paravirt: remove 32-bit support from PARAVIRT_XXL
x86/paravirt: cleanup paravirt macros
x86/paravirt: use CONFIG_PARAVIRT_XXL instead of CONFIG_PARAVIRT
x86/entry/32: revert "Fix XEN_PV build dependency"

arch/x86/entry/entry_32.S | 109 +----
arch/x86/entry/entry_64.S | 4 +-
arch/x86/entry/vdso/vdso32/note.S | 30 --
arch/x86/entry/vdso/vdso32/vclock_gettime.c | 1 +
arch/x86/include/asm/fixmap.h | 2 +-
arch/x86/include/asm/idtentry.h | 4 +-
arch/x86/include/asm/paravirt.h | 107 +----
arch/x86/include/asm/paravirt_types.h | 21 -
arch/x86/include/asm/pgtable-3level_types.h | 5 -
arch/x86/include/asm/proto.h | 2 +-
arch/x86/include/asm/required-features.h | 2 +-
arch/x86/include/asm/segment.h | 6 +-
arch/x86/kernel/cpu/common.c | 8 -
arch/x86/kernel/head_32.S | 31 --
arch/x86/kernel/kprobes/core.c | 1 -
arch/x86/kernel/kprobes/opt.c | 1 -
arch/x86/kernel/paravirt.c | 18 -
arch/x86/kernel/paravirt_patch.c | 17 -
arch/x86/xen/Kconfig | 3 +-
arch/x86/xen/Makefile | 3 +-
arch/x86/xen/apic.c | 17 -
arch/x86/xen/enlighten_pv.c | 78 +---
arch/x86/xen/mmu_pv.c | 488 ++++----------------
arch/x86/xen/p2m.c | 6 +-
arch/x86/xen/setup.c | 36 +-
arch/x86/xen/smp_pv.c | 18 -
arch/x86/xen/vdso.h | 6 -
arch/x86/xen/xen-asm.S | 193 +++++++-
arch/x86/xen/xen-asm_32.S | 185 --------
arch/x86/xen/xen-asm_64.S | 192 --------
arch/x86/xen/xen-head.S | 6 -
drivers/xen/Kconfig | 4 +-
32 files changed, 305 insertions(+), 1299 deletions(-)
delete mode 100644 arch/x86/xen/vdso.h
delete mode 100644 arch/x86/xen/xen-asm_32.S
delete mode 100644 arch/x86/xen/xen-asm_64.S

--
2.26.2