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arch-x86: Specialize LLDT for 64 bit and non-64 bit.

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In 64 bit mode the LLDT has a 128 bit descriptor which takes up two
slots. In any other mode, the descriptor is still 64 bits.

Change-Id: I88d3758a66dec3482153df5ec08565427d6c9269
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/55884
Maintainer: Gabe Black <gabe.black@gmail.com>
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Maintainer: Matt Sinclair <mattdsinclair@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This commit is contained in:
Gabe Black
2022-01-23 22:14:03 -08:00
parent 51648570ea
commit 013a90c969
2 changed files with 61 additions and 24 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
src/arch/x86/isa/decoder/two_byte_opcodes.isa
View File

@@ -48,7 +48,10 @@
0x00: decode MODRM_REG {
0x0: sldt_Mw_or_Rv();
0x1: str_Mw_or_Rv();
0x2: Inst::LLDT(Ew);
0x2: decode MODE_SUBMODE {
0x0: Inst::LLDT_64(Ew);
default: Inst::LLDT(Ew);
}
0x3: Inst::LTR(Ew);
0x4: verr_Mw_or_Rv();
0x5: verw_Mw_or_Rv();

80
src/arch/x86/isa/insts/system/segmentation.py
View File

@@ -211,6 +211,60 @@ def macroop LTR_P
st t1, tsg, [8, t4, t0], dataSize=8
};
def macroop LLDT_64_R
{
.serialize_after
chks reg, t0, InGDTCheck, flags=(EZF,)
br label("end"), flags=(CEZF,)
limm t4, 0, dataSize=8
srli t4, reg, 3, dataSize=2
ld t1, tsg, [8, t4, t0], dataSize=8
ld t2, tsg, [8, t4, t0], 8, dataSize=8
chks reg, t1, LDTCheck
wrdh t3, t1, t2
wrdl tsl, t1, reg
wrbase tsl, t3, dataSize=8
end:
fault "NoFault"
};
def macroop LLDT_64_M
{
.serialize_after
ld t5, seg, sib, disp, dataSize=2
chks t5, t0, InGDTCheck, flags=(EZF,)
br label("end"), flags=(CEZF,)
limm t4, 0, dataSize=8
srli t4, t5, 3, dataSize=2
ld t1, tsg, [8, t4, t0], dataSize=8
ld t2, tsg, [8, t4, t0], 8, dataSize=8
chks t5, t1, LDTCheck
wrdh t3, t1, t2
wrdl tsl, t1, t5
wrbase tsl, t3, dataSize=8
end:
fault "NoFault"
};
def macroop LLDT_64_P
{
.serialize_after
rdip t7
ld t5, seg, riprel, disp, dataSize=2
chks t5, t0, InGDTCheck, flags=(EZF,)
br label("end"), flags=(CEZF,)
limm t4, 0, dataSize=8
srli t4, t5, 3, dataSize=2
ld t1, tsg, [8, t4, t0], dataSize=8
ld t2, tsg, [8, t4, t0], 8, dataSize=8
chks t5, t1, LDTCheck
wrdh t3, t1, t2
wrdl tsl, t1, t5
wrbase tsl, t3, dataSize=8
end:
fault "NoFault"
};
def macroop LLDT_R
{
.serialize_after
@@ -218,12 +272,9 @@ def macroop LLDT_R
br label("end"), flags=(CEZF,)
limm t4, 0, dataSize=8
srli t4, reg, 3, dataSize=2
ldst t1, tsg, [8, t4, t0], dataSize=8
ld t2, tsg, [8, t4, t0], 8, dataSize=8
ld t1, tsg, [8, t4, t0], dataSize=8
chks reg, t1, LDTCheck
wrdh t3, t1, t2
wrdl tsl, t1, reg
wrbase tsl, t3, dataSize=8
end:
fault "NoFault"
};
@@ -236,33 +287,16 @@ def macroop LLDT_M
br label("end"), flags=(CEZF,)
limm t4, 0, dataSize=8
srli t4, t5, 3, dataSize=2
ldst t1, tsg, [8, t4, t0], dataSize=8
ld t2, tsg, [8, t4, t0], 8, dataSize=8
ld t1, tsg, [8, t4, t0], dataSize=8
chks t5, t1, LDTCheck
wrdh t3, t1, t2
wrdl tsl, t1, t5
wrbase tsl, t3, dataSize=8
end:
fault "NoFault"
};
def macroop LLDT_P
{
.serialize_after
rdip t7
ld t5, seg, riprel, disp, dataSize=2
chks t5, t0, InGDTCheck, flags=(EZF,)
br label("end"), flags=(CEZF,)
limm t4, 0, dataSize=8
srli t4, t5, 3, dataSize=2
ldst t1, tsg, [8, t4, t0], dataSize=8
ld t2, tsg, [8, t4, t0], 8, dataSize=8
chks t5, t1, LDTCheck
wrdh t3, t1, t2
wrdl tsl, t1, t5
wrbase tsl, t3, dataSize=8
end:
fault "NoFault"
panic "LLDT in non-64 bit mode doesn't support RIP addressing."
};
def macroop SWAPGS