d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

There is no need to save and restore the host's return address in the

Browse Source 
'struct vmxctx'. It is preserved on the host stack across a guest entry
and exit and just restoring the host's '%rsp' is sufficient.

Pointed out by:	grehan@
This commit is contained in:
Neel Natu 2014-04-11 20:15:53 +00:00
parent 2ffb755cec
commit 81d597b736
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=264353
3 changed files with 5 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
sys/amd64/vmm/intel/vmx.h
View File

@ -60,7 +60,6 @@ struct vmxctx {
register_t host_rbp;
register_t host_rsp;
register_t host_rbx;
register_t host_rip;
/*
* XXX todo debug registers and fpu state
*/

1
sys/amd64/vmm/intel/vmx_genassym.c
View File

@ -65,7 +65,6 @@ ASSYM(VMXCTX_HOST_R12, offsetof(struct vmxctx, host_r12));
ASSYM(VMXCTX_HOST_RBP, offsetof(struct vmxctx, host_rbp));
ASSYM(VMXCTX_HOST_RSP, offsetof(struct vmxctx, host_rsp));
ASSYM(VMXCTX_HOST_RBX, offsetof(struct vmxctx, host_rbx));
ASSYM(VMXCTX_HOST_RIP, offsetof(struct vmxctx, host_rip));
ASSYM(VMXCTX_INST_FAIL_STATUS, offsetof(struct vmxctx, inst_fail_status));
ASSYM(VMXCTX_PMAP, offsetof(struct vmxctx, pmap));

14
sys/amd64/vmm/intel/vmx_support.S
View File

@ -72,8 +72,7 @@
*
* Assumes that %rdi holds a pointer to the 'vmxctx'.
*/
#define VMX_HOST_SAVE(tmpreg) \
movq (%rsp), tmpreg; /* return address */ \
#define VMX_HOST_SAVE \
movq %r15, VMXCTX_HOST_R15(%rdi); \
movq %r14, VMXCTX_HOST_R14(%rdi); \
movq %r13, VMXCTX_HOST_R13(%rdi); \
@ -81,9 +80,8 @@
movq %rbp, VMXCTX_HOST_RBP(%rdi); \
movq %rsp, VMXCTX_HOST_RSP(%rdi); \
movq %rbx, VMXCTX_HOST_RBX(%rdi); \
movq tmpreg, VMXCTX_HOST_RIP(%rdi)
#define VMX_HOST_RESTORE(tmpreg) \
#define VMX_HOST_RESTORE \
movq VMXCTX_HOST_R15(%rdi), %r15; \
movq VMXCTX_HOST_R14(%rdi), %r14; \
movq VMXCTX_HOST_R13(%rdi), %r13; \
@ -91,8 +89,6 @@
movq VMXCTX_HOST_RBP(%rdi), %rbp; \
movq VMXCTX_HOST_RSP(%rdi), %rsp; \
movq VMXCTX_HOST_RBX(%rdi), %rbx; \
movq VMXCTX_HOST_RIP(%rdi), tmpreg; \
movq tmpreg, (%rsp) /* return address */
/*
* vmx_enter_guest(struct vmxctx *vmxctx, int launched)
@ -105,7 +101,7 @@ ENTRY(vmx_enter_guest)
/*
* Save host state before doing anything else.
*/
VMX_HOST_SAVE(%r10)
VMX_HOST_SAVE
/*
* Activate guest pmap on this cpu.
@ -186,7 +182,7 @@ inst_error:
movl PCPU(CPUID), %r10d
LK btrl %r10d, PM_ACTIVE(%r11)
VMX_HOST_RESTORE(%r10)
VMX_HOST_RESTORE
ret
END(vmx_enter_guest)
@ -226,7 +222,7 @@ ENTRY(vmx_exit_guest)
movl PCPU(CPUID), %r10d
LK btrl %r10d, PM_ACTIVE(%r11)
VMX_HOST_RESTORE(%r10)
VMX_HOST_RESTORE
/*
* This will return to the caller of 'vmx_enter_guest()' with a return