Retrieve special registers (e.g. segment, control, and descriptor
table registers) from MSHV vCPUs.
Various helper functions to map register state representations between
Qemu and MSHV are introduced.
Signed-off-by: Magnus Kulke <magnusku...@linux.microsoft.com>
---
include/system/mshv.h | 1 +
target/i386/mshv/mshv-cpu.c | 105 ++++++++++++++++++++++++++++++++++++
2 files changed, 106 insertions(+)
diff --git a/include/system/mshv.h b/include/system/mshv.h
index 43e2619ddc..6ca82d367b 100644
--- a/include/system/mshv.h
+++ b/include/system/mshv.h
@@ -91,6 +91,7 @@ void mshv_init_cpu_logic(void);
int mshv_create_vcpu(int vm_fd, uint8_t vp_index, int *cpu_fd);
void mshv_remove_vcpu(int vm_fd, int cpu_fd);
int mshv_get_standard_regs(CPUState *cpu);
+int mshv_get_special_regs(CPUState *cpu);
int mshv_run_vcpu(int vm_fd, CPUState *cpu, hv_message *msg, MshvVmExit *exit);
int mshv_load_regs(CPUState *cpu);
int mshv_store_regs(CPUState *cpu);
diff --git a/target/i386/mshv/mshv-cpu.c b/target/i386/mshv/mshv-cpu.c
index cb59d74eb4..53b6722af4 100644
--- a/target/i386/mshv/mshv-cpu.c
+++ b/target/i386/mshv/mshv-cpu.c
@@ -51,6 +51,26 @@ static enum hv_register_name STANDARD_REGISTER_NAMES[18] = {
HV_X64_REGISTER_RFLAGS,
};
+static enum hv_register_name SPECIAL_REGISTER_NAMES[17] = {
+ HV_X64_REGISTER_CS,
+ HV_X64_REGISTER_DS,
+ HV_X64_REGISTER_ES,
+ HV_X64_REGISTER_FS,
+ HV_X64_REGISTER_GS,
+ HV_X64_REGISTER_SS,
+ HV_X64_REGISTER_TR,
+ HV_X64_REGISTER_LDTR,
+ HV_X64_REGISTER_GDTR,
+ HV_X64_REGISTER_IDTR,
+ HV_X64_REGISTER_CR0,
+ HV_X64_REGISTER_CR2,
+ HV_X64_REGISTER_CR3,
+ HV_X64_REGISTER_CR4,
+ HV_X64_REGISTER_CR8,
+ HV_X64_REGISTER_EFER,
+ HV_X64_REGISTER_APIC_BASE,
+};
+
int mshv_set_generic_regs(int cpu_fd, hv_register_assoc *assocs, size_t n_regs)
{
struct mshv_vp_registers input = {
@@ -174,6 +194,85 @@ int mshv_get_standard_regs(CPUState *cpu)
return 0;
}
+static inline void populate_segment_reg(const hv_x64_segment_register *hv_seg,
+ SegmentCache *seg)
+{
+ memset(seg, 0, sizeof(SegmentCache));
+
+ seg->base = hv_seg->base;
+ seg->limit = hv_seg->limit;
+ seg->selector = hv_seg->selector;
+
+ seg->flags = (hv_seg->segment_type << DESC_TYPE_SHIFT)
+ | (hv_seg->present * DESC_P_MASK)
+ | (hv_seg->descriptor_privilege_level << DESC_DPL_SHIFT)
+ | (hv_seg->_default << DESC_B_SHIFT)
+ | (hv_seg->non_system_segment * DESC_S_MASK)
+ | (hv_seg->_long << DESC_L_SHIFT)
+ | (hv_seg->granularity * DESC_G_MASK)
+ | (hv_seg->available * DESC_AVL_MASK);
+
+}
+
+static inline void populate_table_reg(const hv_x64_table_register *hv_seg,
+ SegmentCache *tbl)
+{
+ memset(tbl, 0, sizeof(SegmentCache));
+
+ tbl->base = hv_seg->base;
+ tbl->limit = hv_seg->limit;
+}
+
+static void populate_special_regs(const hv_register_assoc *assocs,
+ X86CPU *x86cpu)
+{
+ CPUX86State *env = &x86cpu->env;
+
+ populate_segment_reg(&assocs[0].value.segment, &env->segs[R_CS]);
+ populate_segment_reg(&assocs[1].value.segment, &env->segs[R_DS]);
+ populate_segment_reg(&assocs[2].value.segment, &env->segs[R_ES]);
+ populate_segment_reg(&assocs[3].value.segment, &env->segs[R_FS]);
+ populate_segment_reg(&assocs[4].value.segment, &env->segs[R_GS]);
+ populate_segment_reg(&assocs[5].value.segment, &env->segs[R_SS]);
+
+ populate_segment_reg(&assocs[6].value.segment, &env->tr);
+ populate_segment_reg(&assocs[7].value.segment, &env->ldt);
+
+ populate_table_reg(&assocs[8].value.table, &env->gdt);
+ populate_table_reg(&assocs[9].value.table, &env->idt);
+
+ env->cr[0] = assocs[10].value.reg64;
+ env->cr[2] = assocs[11].value.reg64;
+ env->cr[3] = assocs[12].value.reg64;
+ env->cr[4] = assocs[13].value.reg64;
+
+ cpu_set_apic_tpr(x86cpu->apic_state, assocs[14].value.reg64);
+ env->efer = assocs[15].value.reg64;
+ cpu_set_apic_base(x86cpu->apic_state, assocs[16].value.reg64);
+}
+
+
+int mshv_get_special_regs(CPUState *cpu)
+{
+ struct hv_register_assoc assocs[ARRAY_SIZE(SPECIAL_REGISTER_NAMES)];
+ int ret;
+ X86CPU *x86cpu = X86_CPU(cpu);
+ int cpu_fd = mshv_vcpufd(cpu);
+ size_t n_regs = ARRAY_SIZE(SPECIAL_REGISTER_NAMES);
+
+ for (size_t i = 0; i < n_regs; i++) {
+ assocs[i].name = SPECIAL_REGISTER_NAMES[i];
+ }
+ ret = get_generic_regs(cpu_fd, assocs, n_regs);
+ if (ret < 0) {
+ error_report("failed to get special registers");
+ return -errno;
+ }
+
+ populate_special_regs(assocs, x86cpu);
+ return 0;
+}
+
int mshv_load_regs(CPUState *cpu)
{
int ret;
@@ -184,6 +283,12 @@ int mshv_load_regs(CPUState *cpu)
return -1;
}
+ ret = mshv_get_special_regs(cpu);
+ if (ret < 0) {
+ error_report("Failed to load special registers");
+ return -1;
+ }
+
return 0;
}
--
2.34.1
