debuggers.hg
changeset 17086:0769835cf50f
x86 shadow: Reduce scope of shadow lock.
emulate_map_dest doesn't require holding lock, since
only shadow related operation possibly involved is to
remove shadow which is less frequent and can acquire
lock inside. Rest are either guest table walk or
per-vcpu monitor table manipulation
Signed-off-by Kevin Tian <kevin.tian@intel.com>
emulate_map_dest doesn't require holding lock, since
only shadow related operation possibly involved is to
remove shadow which is less frequent and can acquire
lock inside. Rest are either guest table walk or
per-vcpu monitor table manipulation
Signed-off-by Kevin Tian <kevin.tian@intel.com>
| author | Keir Fraser <keir.fraser@citrix.com> |
|---|---|
| date | Thu Feb 14 10:33:12 2008 +0000 (2008-02-14) |
| parents | 80428fb872be |
| children | c9d9bbf1204c |
| files | xen/arch/x86/mm/shadow/multi.c |
line diff
1.1 --- a/xen/arch/x86/mm/shadow/multi.c Thu Feb 14 10:31:01 2008 +0000 1.2 +++ b/xen/arch/x86/mm/shadow/multi.c Thu Feb 14 10:33:12 2008 +0000 1.3 @@ -4216,15 +4216,12 @@ sh_x86_emulate_write(struct vcpu *v, uns 1.4 if ( (vaddr & (bytes - 1)) && !is_hvm_vcpu(v) ) 1.5 return X86EMUL_UNHANDLEABLE; 1.6 1.7 - shadow_lock(v->domain); 1.8 addr = emulate_map_dest(v, vaddr, bytes, sh_ctxt); 1.9 if ( emulate_map_dest_failed(addr) ) 1.10 - { 1.11 - shadow_unlock(v->domain); 1.12 return ((addr == MAPPING_EXCEPTION) ? 1.13 X86EMUL_EXCEPTION : X86EMUL_UNHANDLEABLE); 1.14 - } 1.15 - 1.16 + 1.17 + shadow_lock(v->domain); 1.18 memcpy(addr, src, bytes); 1.19 1.20 emulate_unmap_dest(v, addr, bytes, sh_ctxt); 1.21 @@ -4246,16 +4243,12 @@ sh_x86_emulate_cmpxchg(struct vcpu *v, u 1.22 if ( (vaddr & (bytes - 1)) && !is_hvm_vcpu(v) ) 1.23 return X86EMUL_UNHANDLEABLE; 1.24 1.25 - shadow_lock(v->domain); 1.26 - 1.27 addr = emulate_map_dest(v, vaddr, bytes, sh_ctxt); 1.28 if ( emulate_map_dest_failed(addr) ) 1.29 - { 1.30 - shadow_unlock(v->domain); 1.31 return ((addr == MAPPING_EXCEPTION) ? 1.32 X86EMUL_EXCEPTION : X86EMUL_UNHANDLEABLE); 1.33 - } 1.34 - 1.35 + 1.36 + shadow_lock(v->domain); 1.37 switch ( bytes ) 1.38 { 1.39 case 1: prev = cmpxchg(((u8 *)addr), old, new); break; 1.40 @@ -4294,18 +4287,15 @@ sh_x86_emulate_cmpxchg8b(struct vcpu *v, 1.41 if ( (vaddr & 7) && !is_hvm_vcpu(v) ) 1.42 return X86EMUL_UNHANDLEABLE; 1.43 1.44 - shadow_lock(v->domain); 1.45 - 1.46 addr = emulate_map_dest(v, vaddr, 8, sh_ctxt); 1.47 if ( emulate_map_dest_failed(addr) ) 1.48 - { 1.49 - shadow_unlock(v->domain); 1.50 return ((addr == MAPPING_EXCEPTION) ? 1.51 X86EMUL_EXCEPTION : X86EMUL_UNHANDLEABLE); 1.52 - } 1.53 1.54 old = (((u64) old_hi) << 32) | (u64) old_lo; 1.55 new = (((u64) new_hi) << 32) | (u64) new_lo; 1.56 + 1.57 + shadow_lock(v->domain); 1.58 prev = cmpxchg(((u64 *)addr), old, new); 1.59 1.60 if ( prev != old )