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| author | Nadav Amit <namit@vmware.com> | 2020-06-23 01:41:32 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-06-24 02:47:10 -0400 |
| commit | d68a795a213ddcd224a80fb9e5015b57582bc625 (patch) | |
| tree | cf068c6dd6752b041efbd221578aa8b926b0e905 | |
| parent | 1b9d2ef25d1758d3f1a12da0e43517e8e5e2ac78 (diff) | |
| download | kvm-unit-tests-d68a795a213ddcd224a80fb9e5015b57582bc625.tar.gz | |
x86: Initialize segment selectors
Currently, the BSP's segment selectors are not initialized in 32-bit
(cstart.S). As a result the tests implicitly rely on the segment
selector values that are set by the BIOS. If this assumption is not
kept, the task-switch test fails.
Fix it by initializing them.
Signed-off-by: Nadav Amit <namit@vmware.com>
Message-Id: <20200623084132.36213-1-namit@vmware.com>
Reviewed-by: Jim Mattson <jmattson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | x86/cstart.S | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/x86/cstart.S b/x86/cstart.S index fa62e09..5ad70b5 100644 --- a/x86/cstart.S +++ b/x86/cstart.S @@ -94,6 +94,15 @@ MSR_GS_BASE = 0xc0000101 wrmsr .endm +.macro setup_segments + mov $0x10, %ax + mov %ax, %ds + mov %ax, %es + mov %ax, %fs + mov %ax, %gs + mov %ax, %ss +.endm + .globl start start: mov $stacktop, %esp @@ -109,6 +118,7 @@ start: prepare_32: lgdtl gdt32_descr + setup_segments mov %cr4, %eax bts $4, %eax // pse @@ -133,12 +143,7 @@ save_id: retl ap_start32: - mov $0x10, %ax - mov %ax, %ds - mov %ax, %es - mov %ax, %fs - mov %ax, %gs - mov %ax, %ss + setup_segments mov $-4096, %esp lock/xaddl %esp, smp_stacktop setup_percpu_area |