[PATCH 5/8] i386: hvf: Don't duplicate register reset

[Roman Bolshakov]

hvf_reset_vcpu() duplicates actions performed by x86_cpu_reset(). The
difference is that hvf_reset_vcpu() stores initial values directly to
VMCS while x86_cpu_reset() stores it in CPUX86State and then
cpu_synchronize_all_post_init() or cpu_synchronize_all_post_reset()
flushes CPUX86State into VMCS. That makes most of the hvf_reset_vcpu() a
kind of no-op.

Here's the trace of CPU state modifications during VM start:
  hvf_reset_vcpu (resets VMCS)
  cpu_synchronize_all_post_init (overwrites VMCS fields written by
                                 hvf_reset_vcpu())
  cpu_synchronize_all_states
  hvf_reset_vcpu (resets VMCS)
  cpu_synchronize_all_post_reset (overwrites VMCS fields written by
                                  hvf_reset_vcpu())

General purpose registers, system registers, segment descriptors, flags
and IP are set by hvf_put_segments() in post-init and post-reset,
therefore it's safe to remove them from hvf_reset_vcpu().

Cc: Cameron Esfahani <dirty@apple.com>
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
---
 target/i386/hvf/hvf.c | 78 -------------------------------------------
 1 file changed, 78 deletions(-)

diff --git a/target/i386/hvf/hvf.c b/target/i386/hvf/hvf.c
index 4d254a477a..2c4028d08c 100644
--- a/target/i386/hvf/hvf.c
+++ b/target/i386/hvf/hvf.c
@@ -456,90 +456,12 @@ void hvf_reset_vcpu(CPUState *cpu) {
     uint64_t pdpte[4] = {0, 0, 0, 0};
     int i;
 
-    /* TODO: this shouldn't be needed; there is already a call to
-     * cpu_synchronize_all_post_reset in vl.c
-     */
     wvmcs(cpu->hvf_fd, VMCS_ENTRY_CTLS, 0);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_IA32_EFER, 0);
 
     /* Initialize PDPTE */
     for (i = 0; i < 4; i++) {
         wvmcs(cpu->hvf_fd, VMCS_GUEST_PDPTE0 + i * 2, pdpte[i]);
     }
-
-    macvm_set_cr0(cpu->hvf_fd, 0x60000010);
-
-    wvmcs(cpu->hvf_fd, VMCS_CR4_MASK, CR4_VMXE_MASK);
-    wvmcs(cpu->hvf_fd, VMCS_CR4_SHADOW, 0x0);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_CR4, CR4_VMXE_MASK);
-
-    /* set VMCS guest state fields */
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_CS_SELECTOR, 0xf000);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_CS_LIMIT, 0xffff);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_CS_ACCESS_RIGHTS, 0x9b);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_CS_BASE, 0xffff0000);
-
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_DS_SELECTOR, 0);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_DS_LIMIT, 0xffff);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_DS_ACCESS_RIGHTS, 0x93);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_DS_BASE, 0);
-
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_ES_SELECTOR, 0);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_ES_LIMIT, 0xffff);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_ES_ACCESS_RIGHTS, 0x93);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_ES_BASE, 0);
-
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_FS_SELECTOR, 0);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_FS_LIMIT, 0xffff);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_FS_ACCESS_RIGHTS, 0x93);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_FS_BASE, 0);
-
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_GS_SELECTOR, 0);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_GS_LIMIT, 0xffff);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_GS_ACCESS_RIGHTS, 0x93);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_GS_BASE, 0);
-
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_SS_SELECTOR, 0);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_SS_LIMIT, 0xffff);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_SS_ACCESS_RIGHTS, 0x93);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_SS_BASE, 0);
-
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_LDTR_SELECTOR, 0);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_LDTR_LIMIT, 0);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_LDTR_ACCESS_RIGHTS, 0x10000);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_LDTR_BASE, 0);
-
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_TR_SELECTOR, 0);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_TR_LIMIT, 0);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_TR_ACCESS_RIGHTS, 0x83);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_TR_BASE, 0);
-
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_GDTR_LIMIT, 0);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_GDTR_BASE, 0);
-
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_IDTR_LIMIT, 0);
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_IDTR_BASE, 0);
-
-    /*wvmcs(cpu->hvf_fd, VMCS_GUEST_CR2, 0x0);*/
-    wvmcs(cpu->hvf_fd, VMCS_GUEST_CR3, 0x0);
-
-    wreg(cpu->hvf_fd, HV_X86_RIP, 0xfff0);
-    wreg(cpu->hvf_fd, HV_X86_RDX, 0x623);
-    wreg(cpu->hvf_fd, HV_X86_RFLAGS, 0x2);
-    wreg(cpu->hvf_fd, HV_X86_RSP, 0x0);
-    wreg(cpu->hvf_fd, HV_X86_RAX, 0x0);
-    wreg(cpu->hvf_fd, HV_X86_RBX, 0x0);
-    wreg(cpu->hvf_fd, HV_X86_RCX, 0x0);
-    wreg(cpu->hvf_fd, HV_X86_RSI, 0x0);
-    wreg(cpu->hvf_fd, HV_X86_RDI, 0x0);
-    wreg(cpu->hvf_fd, HV_X86_RBP, 0x0);
-
-    for (int i = 0; i < 8; i++) {
-        wreg(cpu->hvf_fd, HV_X86_R8 + i, 0x0);
-    }
-
-    hv_vcpu_invalidate_tlb(cpu->hvf_fd);
-    hv_vcpu_flush(cpu->hvf_fd);
 }
 
 void hvf_vcpu_destroy(CPUState *cpu)
-- 
2.26.1