qemu/include/sysemu/hvf.h
Roman Bolshakov 5009ef22c6 i386: hvf: Don't duplicate register reset
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 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().

PDPTE initialization can be dropped because Intel SDM (26.3.1.6 Checks
on Guest Page-Directory-Pointer-Table Entries) doesn't require PDPTE to
be clear unless PAE is used: "A VM entry to a guest that does not use
PAE paging does not check the validity of any PDPTEs."
And if PAE is used, PDPTE's are initialized from CR3 in macvm_set_cr0().

Cc: Cameron Esfahani <dirty@apple.com>
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200630102824.77604-8-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10 18:02:19 -04:00

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C

/*
* QEMU Hypervisor.framework (HVF) support
*
* Copyright Google Inc., 2017
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
/* header to be included in non-HVF-specific code */
#ifndef HVF_H
#define HVF_H
#ifdef CONFIG_HVF
uint32_t hvf_get_supported_cpuid(uint32_t func, uint32_t idx,
int reg);
extern bool hvf_allowed;
#define hvf_enabled() (hvf_allowed)
#else /* !CONFIG_HVF */
#define hvf_enabled() 0
#define hvf_get_supported_cpuid(func, idx, reg) 0
#endif /* !CONFIG_HVF */
int hvf_init_vcpu(CPUState *);
int hvf_vcpu_exec(CPUState *);
void hvf_cpu_synchronize_state(CPUState *);
void hvf_cpu_synchronize_post_reset(CPUState *);
void hvf_cpu_synchronize_post_init(CPUState *);
void hvf_cpu_synchronize_pre_loadvm(CPUState *);
void hvf_vcpu_destroy(CPUState *);
#define TYPE_HVF_ACCEL ACCEL_CLASS_NAME("hvf")
#define HVF_STATE(obj) \
OBJECT_CHECK(HVFState, (obj), TYPE_HVF_ACCEL)
#endif