From 8c2e41f7ae1234c192ef497472ad306227c77c03 Mon Sep 17 00:00:00 2001
From: Andy Lutomirski <luto@kernel.org>
Date: Mon, 20 Feb 2017 08:56:12 -0800
Subject: [PATCH] x86/kvm/vmx: Simplify segment_base()
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Use actual pointer types for pointers (instead of unsigned long) and
replace hardcoded constants with the appropriate self-documenting
macros.
The function is still a bit messy, but this seems a lot better than
before to me.
This is mostly borrowed from a patch by Thomas Garnier.
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/vmx.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 3ddd72303fe4a..2dd94cf597ccd 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2067,24 +2067,23 @@ static unsigned long segment_base(u16 selector)
{
struct desc_ptr *gdt = this_cpu_ptr(&host_gdt);
struct desc_struct *d;
- unsigned long table_base;
+ struct desc_struct *table;
unsigned long v;
- if (!(selector & ~3))
+ if (!(selector & ~SEGMENT_RPL_MASK))
return 0;
- table_base = gdt->address;
+ table = (struct desc_struct *)gdt->address;
- if (selector & 4) { /* from ldt */
+ if ((selector & SEGMENT_TI_MASK) == SEGMENT_LDT) {
u16 ldt_selector = kvm_read_ldt();
- if (!(ldt_selector & ~3))
+ if (!(ldt_selector & ~SEGMENT_RPL_MASK))
return 0;
- table_base = segment_base(ldt_selector);
+ table = (struct desc_struct *)segment_base(ldt_selector);
}
- d = (struct desc_struct *)(table_base + (selector & ~7));
- v = get_desc_base(d);
+ v = get_desc_base(&table[selector >> 3]);
return v;
}
#endif