[PATCH v2 09/11] KVM: x86: emulator/smm: use smram struct for 64 bit smram load/restore

Maxim Levitsky
2022-06-21T15:10:06Z

Use kvm_smram_state_64 struct to save/restore the 64 bit SMM state
(used when X86_FEATURE_LM is present in the guest CPUID,
regardless of 32-bitness of the guest).

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
---
arch/x86/kvm/emulate.c | 88 ++++++++++++++----------------------------
arch/x86/kvm/x86.c | 75 ++++++++++++++++-------------------
2 files changed, 62 insertions(+), 101 deletions(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 6d263906054689..7a3a042d6b862a 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2381,24 +2381,16 @@ static void rsm_load_seg_32(struct x86_emulate_ctxt *ctxt,
}

#ifdef CONFIG_X86_64
-static int rsm_load_seg_64(struct x86_emulate_ctxt *ctxt, const char *smstate,
- int n)
+static void rsm_load_seg_64(struct x86_emulate_ctxt *ctxt,
+ struct kvm_smm_seg_state_64 *state,
+ int n)
{
struct desc_struct desc;
- int offset;
- u16 selector;
- u32 base3;
-
- offset = 0x7e00 + n * 16;
-
- selector = GET_SMSTATE(u16, smstate, offset);
- rsm_set_desc_flags(&desc, GET_SMSTATE(u16, smstate, offset + 2) << 8);
- set_desc_limit(&desc, GET_SMSTATE(u32, smstate, offset + 4));
- set_desc_base(&desc, GET_SMSTATE(u32, smstate, offset + 8));
- base3 = GET_SMSTATE(u32, smstate, offset + 12);

- ctxt->ops->set_segment(ctxt, selector, &desc, base3, n);
- return X86EMUL_CONTINUE;
+ rsm_set_desc_flags(&desc, state->attributes << 8);
+ set_desc_limit(&desc, state->limit);
+ set_desc_base(&desc, (u32)state->base);
+ ctxt->ops->set_segment(ctxt, state->selector, &desc, state->base >> 32, n);
}
#endif

@@ -2492,71 +2484,49 @@ static int rsm_load_state_32(struct x86_emulate_ctxt *ctxt,

#ifdef CONFIG_X86_64
static int rsm_load_state_64(struct x86_emulate_ctxt *ctxt,
- const char *smstate)
+ struct kvm_smram_state_64 *smstate)
{
- struct desc_struct desc;
struct desc_ptr dt;
- u64 val, cr0, cr3, cr4;
- u32 base3;
- u16 selector;
int i, r;

for (i = 0; i < 16; i++)
- *reg_write(ctxt, i) = GET_SMSTATE(u64, smstate, 0x7ff8 - i * 8);
+ *reg_write(ctxt, i) = smstate->gprs[15 - i];

- ctxt->_eip = GET_SMSTATE(u64, smstate, 0x7f78);
- ctxt->eflags = GET_SMSTATE(u32, smstate, 0x7f70) | X86_EFLAGS_FIXED;
+ ctxt->_eip = smstate->rip;
+ ctxt->eflags = smstate->rflags | X86_EFLAGS_FIXED;

- val = GET_SMSTATE(u64, smstate, 0x7f68);
-
- if (ctxt->ops->set_dr(ctxt, 6, val))
+ if (ctxt->ops->set_dr(ctxt, 6, smstate->dr6))
return X86EMUL_UNHANDLEABLE;
-
- val = GET_SMSTATE(u64, smstate, 0x7f60);
-
- if (ctxt->ops->set_dr(ctxt, 7, val))
+ if (ctxt->ops->set_dr(ctxt, 7, smstate->dr7))
return X86EMUL_UNHANDLEABLE;

- cr0 = GET_SMSTATE(u64, smstate, 0x7f58);
- cr3 = GET_SMSTATE(u64, smstate, 0x7f50);
- cr4 = GET_SMSTATE(u64, smstate, 0x7f48);
- ctxt->ops->set_smbase(ctxt, GET_SMSTATE(u32, smstate, 0x7f00));
- val = GET_SMSTATE(u64, smstate, 0x7ed0);
+ ctxt->ops->set_smbase(ctxt, smstate->smbase);

- if (ctxt->ops->set_msr(ctxt, MSR_EFER, val & ~EFER_LMA))
+ if (ctxt->ops->set_msr(ctxt, MSR_EFER, smstate->efer & ~EFER_LMA))
return X86EMUL_UNHANDLEABLE;

- selector = GET_SMSTATE(u32, smstate, 0x7e90);
- rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smstate, 0x7e92) << 8);
- set_desc_limit(&desc, GET_SMSTATE(u32, smstate, 0x7e94));
- set_desc_base(&desc, GET_SMSTATE(u32, smstate, 0x7e98));
- base3 = GET_SMSTATE(u32, smstate, 0x7e9c);
- ctxt->ops->set_segment(ctxt, selector, &desc, base3, VCPU_SREG_TR);
+ rsm_load_seg_64(ctxt, &smstate->tr, VCPU_SREG_TR);

- dt.size = GET_SMSTATE(u32, smstate, 0x7e84);
- dt.address = GET_SMSTATE(u64, smstate, 0x7e88);
+ dt.size = smstate->idtr.limit;
+ dt.address = smstate->idtr.base;
ctxt->ops->set_idt(ctxt, &dt);

- selector = GET_SMSTATE(u32, smstate, 0x7e70);
- rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smstate, 0x7e72) << 8);
- set_desc_limit(&desc, GET_SMSTATE(u32, smstate, 0x7e74));
- set_desc_base(&desc, GET_SMSTATE(u32, smstate, 0x7e78));
- base3 = GET_SMSTATE(u32, smstate, 0x7e7c);
- ctxt->ops->set_segment(ctxt, selector, &desc, base3, VCPU_SREG_LDTR);
+ rsm_load_seg_64(ctxt, &smstate->ldtr, VCPU_SREG_LDTR);

- dt.size = GET_SMSTATE(u32, smstate, 0x7e64);
- dt.address = GET_SMSTATE(u64, smstate, 0x7e68);
+ dt.size = smstate->gdtr.limit;
+ dt.address = smstate->gdtr.base;
ctxt->ops->set_gdt(ctxt, &dt);

- r = rsm_enter_protected_mode(ctxt, cr0, cr3, cr4);
+ r = rsm_enter_protected_mode(ctxt, smstate->cr0, smstate->cr3, smstate->cr4);
if (r != X86EMUL_CONTINUE)
return r;

- for (i = 0; i < 6; i++) {
- r = rsm_load_seg_64(ctxt, smstate, i);
- if (r != X86EMUL_CONTINUE)
- return r;
- }
+ rsm_load_seg_64(ctxt, &smstate->es, VCPU_SREG_ES);
+ rsm_load_seg_64(ctxt, &smstate->cs, VCPU_SREG_CS);
+ rsm_load_seg_64(ctxt, &smstate->ss, VCPU_SREG_SS);
+ rsm_load_seg_64(ctxt, &smstate->ds, VCPU_SREG_DS);
+ rsm_load_seg_64(ctxt, &smstate->fs, VCPU_SREG_FS);
+ rsm_load_seg_64(ctxt, &smstate->gs, VCPU_SREG_GS);

return X86EMUL_CONTINUE;
}
@@ -2629,7 +2599,7 @@ static int em_rsm(struct x86_emulate_ctxt *ctxt)

#ifdef CONFIG_X86_64
if (emulator_has_longmode(ctxt))
- ret = rsm_load_state_64(ctxt, buf);
+ ret = rsm_load_state_64(ctxt, (struct kvm_smram_state_64 *)buf);
else
#endif
ret = rsm_load_state_32(ctxt, (struct kvm_smram_state_32 *)buf);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a1bbf2ed520769..a1b138f0815d30 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9689,20 +9689,17 @@ static void enter_smm_save_seg_32(struct kvm_vcpu *vcpu,
}

#ifdef CONFIG_X86_64
-static void enter_smm_save_seg_64(struct kvm_vcpu *vcpu, char *buf, int n)
+static void enter_smm_save_seg_64(struct kvm_vcpu *vcpu,
+ struct kvm_smm_seg_state_64 *state,
+ int n)
{
struct kvm_segment seg;
- int offset;
- u16 flags;

kvm_get_segment(vcpu, &seg, n);
- offset = 0x7e00 + n * 16;
-
- flags = enter_smm_get_segment_flags(&seg) >> 8;
- put_smstate(u16, buf, offset, seg.selector);
- put_smstate(u16, buf, offset + 2, flags);
- put_smstate(u32, buf, offset + 4, seg.limit);
- put_smstate(u64, buf, offset + 8, seg.base);
+ state->selector = seg.selector;
+ state->attributes = enter_smm_get_segment_flags(&seg) >> 8;
+ state->limit = seg.limit;
+ state->base = seg.base;
}
#endif

@@ -9750,57 +9747,51 @@ static void enter_smm_save_state_32(struct kvm_vcpu *vcpu, struct kvm_smram_stat
}

#ifdef CONFIG_X86_64
-static void enter_smm_save_state_64(struct kvm_vcpu *vcpu, char *buf)
+static void enter_smm_save_state_64(struct kvm_vcpu *vcpu, struct kvm_smram_state_64 *smram)
{
struct desc_ptr dt;
- struct kvm_segment seg;
unsigned long val;
int i;

for (i = 0; i < 16; i++)
- put_smstate(u64, buf, 0x7ff8 - i * 8, kvm_register_read_raw(vcpu, i));
+ smram->gprs[15 - i] = kvm_register_read_raw(vcpu, i);
+
+ smram->rip = kvm_rip_read(vcpu);
+ smram->rflags = kvm_get_rflags(vcpu);

- put_smstate(u64, buf, 0x7f78, kvm_rip_read(vcpu));
- put_smstate(u32, buf, 0x7f70, kvm_get_rflags(vcpu));

kvm_get_dr(vcpu, 6, &val);
- put_smstate(u64, buf, 0x7f68, val);
+ smram->dr6 = val;
kvm_get_dr(vcpu, 7, &val);
- put_smstate(u64, buf, 0x7f60, val);
-
- put_smstate(u64, buf, 0x7f58, kvm_read_cr0(vcpu));
- put_smstate(u64, buf, 0x7f50, kvm_read_cr3(vcpu));
- put_smstate(u64, buf, 0x7f48, kvm_read_cr4(vcpu));
+ smram->dr7 = val;

- put_smstate(u32, buf, 0x7f00, vcpu->arch.smbase);
+ smram->cr0 = kvm_read_cr0(vcpu);
+ smram->cr3 = kvm_read_cr3(vcpu);
+ smram->cr4 = kvm_read_cr4(vcpu);

- /* revision id */
- put_smstate(u32, buf, 0x7efc, 0x00020064);
+ smram->smbase = vcpu->arch.smbase;
+ smram->smm_revison = 0x00020064;

- put_smstate(u64, buf, 0x7ed0, vcpu->arch.efer);
+ smram->efer = vcpu->arch.efer;

- kvm_get_segment(vcpu, &seg, VCPU_SREG_TR);
- put_smstate(u16, buf, 0x7e90, seg.selector);
- put_smstate(u16, buf, 0x7e92, enter_smm_get_segment_flags(&seg) >> 8);
- put_smstate(u32, buf, 0x7e94, seg.limit);
- put_smstate(u64, buf, 0x7e98, seg.base);
+ enter_smm_save_seg_64(vcpu, &smram->tr, VCPU_SREG_TR);

static_call(kvm_x86_get_idt)(vcpu, &dt);
- put_smstate(u32, buf, 0x7e84, dt.size);
- put_smstate(u64, buf, 0x7e88, dt.address);
+ smram->idtr.limit = dt.size;
+ smram->idtr.base = dt.address;

- kvm_get_segment(vcpu, &seg, VCPU_SREG_LDTR);
- put_smstate(u16, buf, 0x7e70, seg.selector);
- put_smstate(u16, buf, 0x7e72, enter_smm_get_segment_flags(&seg) >> 8);
- put_smstate(u32, buf, 0x7e74, seg.limit);
- put_smstate(u64, buf, 0x7e78, seg.base);
+ enter_smm_save_seg_64(vcpu, &smram->ldtr, VCPU_SREG_LDTR);

static_call(kvm_x86_get_gdt)(vcpu, &dt);
- put_smstate(u32, buf, 0x7e64, dt.size);
- put_smstate(u64, buf, 0x7e68, dt.address);
+ smram->gdtr.limit = dt.size;
+ smram->gdtr.base = dt.address;

- for (i = 0; i < 6; i++)
- enter_smm_save_seg_64(vcpu, buf, i);
+ enter_smm_save_seg_64(vcpu, &smram->es, VCPU_SREG_ES);
+ enter_smm_save_seg_64(vcpu, &smram->cs, VCPU_SREG_CS);
+ enter_smm_save_seg_64(vcpu, &smram->ss, VCPU_SREG_SS);
+ enter_smm_save_seg_64(vcpu, &smram->ds, VCPU_SREG_DS);
+ enter_smm_save_seg_64(vcpu, &smram->fs, VCPU_SREG_FS);
+ enter_smm_save_seg_64(vcpu, &smram->gs, VCPU_SREG_GS);
}
#endif

@@ -9814,7 +9805,7 @@ static void enter_smm(struct kvm_vcpu *vcpu)
memset(buf, 0, 512);
#ifdef CONFIG_X86_64
if (guest_cpuid_has(vcpu, X86_FEATURE_LM))
- enter_smm_save_state_64(vcpu, buf);
+ enter_smm_save_state_64(vcpu, (struct kvm_smram_state_64 *)buf);
else
#endif
enter_smm_save_state_32(vcpu, (struct kvm_smram_state_32 *)buf);
--
2.26.3