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target/i386: add control bits support for LAM 

LAM uses CR3[61] and CR3[62] to configure/enable LAM on user pointers.
LAM uses CR4[28] to configure/enable LAM on supervisor pointers.

For CR3 LAM bits, no additional handling needed:
- TCG
  LAM is not supported for TCG of target-i386.  helper_write_crN() and
  helper_vmrun() check max physical address bits before calling
  cpu_x86_update_cr3(), no change needed, i.e. CR3 LAM bits are not allowed
  to be set in TCG.
- gdbstub
  x86_cpu_gdb_write_register() will call cpu_x86_update_cr3() to update cr3.
  Allow gdb to set the LAM bit(s) to CR3, if vcpu doesn't support LAM,
  KVM_SET_SREGS will fail as other reserved bits.

For CR4 LAM bit, its reservation depends on vcpu supporting LAM feature or
not.
- TCG
  LAM is not supported for TCG of target-i386.  helper_write_crN() and
  helper_vmrun() check CR4 reserved bit before calling cpu_x86_update_cr4(),
  i.e. CR4 LAM bit is not allowed to be set in TCG.
- gdbstub
  x86_cpu_gdb_write_register() will call cpu_x86_update_cr4() to update cr4.
  Mask out LAM bit on CR4 if vcpu doesn't support LAM.
- x86_cpu_reset_hold() doesn't need special handling.

Signed-off-by: Binbin Wu <binbin.wu@linux.intel.com>
Tested-by: Xuelian Guo <xuelian.guo@intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Message-ID: <20240112060042.19925-3-binbin.wu@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Binbin Wu 2024-01-12 14:00:42 +08:00 committed by Paolo Bonzini
parent ba67809059
commit 0117067131
2 changed files with 10 additions and 1 deletions
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7
target/i386/cpu.h
View File

@ -258,6 +258,7 @@ typedef enum X86Seg {
#define CR4_SMAP_MASK (1U << 21)
#define CR4_PKE_MASK (1U << 22)
#define CR4_PKS_MASK (1U << 24)
#define CR4_LAM_SUP_MASK (1U << 28)
#define CR4_RESERVED_MASK \
(~(target_ulong)(CR4_VME_MASK | CR4_PVI_MASK | CR4_TSD_MASK \
@ -266,7 +267,8 @@ typedef enum X86Seg {
| CR4_OSFXSR_MASK | CR4_OSXMMEXCPT_MASK | CR4_UMIP_MASK \
| CR4_LA57_MASK \
| CR4_FSGSBASE_MASK | CR4_PCIDE_MASK | CR4_OSXSAVE_MASK \
| CR4_SMEP_MASK | CR4_SMAP_MASK | CR4_PKE_MASK | CR4_PKS_MASK))
| CR4_SMEP_MASK | CR4_SMAP_MASK | CR4_PKE_MASK | CR4_PKS_MASK \
| CR4_LAM_SUP_MASK))
#define DR6_BD (1 << 13)
#define DR6_BS (1 << 14)
@ -2563,6 +2565,9 @@ static inline uint64_t cr4_reserved_bits(CPUX86State *env)
if (!(env->features[FEAT_7_0_ECX] & CPUID_7_0_ECX_PKS)) {
reserved_bits |= CR4_PKS_MASK;
}
if (!(env->features[FEAT_7_1_EAX] & CPUID_7_1_EAX_LAM)) {
reserved_bits |= CR4_LAM_SUP_MASK;
}
return reserved_bits;
}

4
target/i386/helper.c
View File

@ -219,6 +219,10 @@ void cpu_x86_update_cr4(CPUX86State *env, uint32_t new_cr4)
new_cr4 &= ~CR4_PKS_MASK;
}
if (!(env->features[FEAT_7_1_EAX] & CPUID_7_1_EAX_LAM)) {
new_cr4 &= ~CR4_LAM_SUP_MASK;
}
env->cr[4] = new_cr4;
env->hflags = hflags;