| Message ID | 1301667024-29420-5-git-send-email-joerg.roedel@amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 04/01/2011 05:10 PM, Joerg Roedel wrote: > This patch adds a check_perm callback for each opcode into > the instruction emulator. This will be used to do all > necessary permission checks on instructions before checking > whether they are intercepted or not. > > > @@ -216,6 +216,7 @@ struct decode_cache { > u8 seg_override; > unsigned int d; > int (*execute)(struct x86_emulate_ctxt *ctxt); > + int (*check_perm)(struct x86_emulate_ctxt *ctxt); I originally mean to use a group-like structure to have check_perm only when needed, but I guess this is a premature optimization. #define D(_y) { .flags = (_y) } > #define DI(_y, _i) { .flags = (_y), .intercept = x86_intercept_##_i } > +#define DIP(_y, _i) { .flags = (_y), .intercept = x86_intercept_##_i, \ > + .check_perm = em_check_perm_##_i } Sorry, this (and all the #defines which follow) are just obfuscating. I set a bad example here, but the following patches show there is nothing gained by the ## games. Please use the full function name.
On Sun, Apr 03, 2011 at 08:35:28AM -0400, Avi Kivity wrote: > On 04/01/2011 05:10 PM, Joerg Roedel wrote: > > This patch adds a check_perm callback for each opcode into > > the instruction emulator. This will be used to do all > > necessary permission checks on instructions before checking > > whether they are intercepted or not. > > > > > > @@ -216,6 +216,7 @@ struct decode_cache { > > u8 seg_override; > > unsigned int d; > > int (*execute)(struct x86_emulate_ctxt *ctxt); > > + int (*check_perm)(struct x86_emulate_ctxt *ctxt); > > I originally mean to use a group-like structure to have check_perm only > when needed, but I guess this is a premature optimization. #define D(_y) > { .flags = (_y) } > > #define DI(_y, _i) { .flags = (_y), .intercept = x86_intercept_##_i } > > +#define DIP(_y, _i) { .flags = (_y), .intercept = x86_intercept_##_i, \ > > + .check_perm = em_check_perm_##_i } > > Sorry, this (and all the #defines which follow) are just obfuscating. I > set a bad example here, but the following patches show there is nothing > gained by the ## games. Please use the full function name. Yeah, this became a bit obfuscating in the end. My intention was to keep the opcode tables clean and readable, but I changed it now and added the check-functions directly removing all the #defines. Joerg
diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h index 366de63..a891051 100644 --- a/arch/x86/include/asm/kvm_emulate.h +++ b/arch/x86/include/asm/kvm_emulate.h @@ -216,6 +216,7 @@ struct decode_cache { u8 seg_override; unsigned int d; int (*execute)(struct x86_emulate_ctxt *ctxt); + int (*check_perm)(struct x86_emulate_ctxt *ctxt); unsigned long regs[NR_VCPU_REGS]; unsigned long eip; /* modrm */ diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index b05e50d..f87d7f8 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -108,6 +108,7 @@ struct opcode { struct opcode *group; struct group_dual *gdual; } u; + int (*check_perm)(struct x86_emulate_ctxt *ctxt); }; struct group_dual { @@ -2328,14 +2329,21 @@ static int em_mov(struct x86_emulate_ctxt *ctxt) #define D(_y) { .flags = (_y) } #define DI(_y, _i) { .flags = (_y), .intercept = x86_intercept_##_i } +#define DIP(_y, _i) { .flags = (_y), .intercept = x86_intercept_##_i, \ + .check_perm = em_check_perm_##_i } #define N D(0) #define G(_f, _g) { .flags = ((_f) | Group), .u.group = (_g) } #define GD(_f, _g) { .flags = ((_f) | Group | GroupDual), .u.gdual = (_g) } #define I(_f, _e) { .flags = (_f), .u.execute = (_e) } #define II(_f, _e, _i) \ { .flags = (_f), .u.execute = (_e), .intercept = x86_intercept_##_i } +#define IIP(_f, _e, _i) \ + { .flags = (_f), .u.execute = (_e), .intercept = x86_intercept_##_i, \ + .check_perm = em_check_perm_##_i } #define D2bv(_f) D((_f) | ByteOp), D(_f) +#define D2bvI(_f, _i) DI((_f) | ByteOp, _i), DI((_f), _i) +#define D2bvIP(_f, _i) DIP((_f) | ByteOp, _i), DIP((_f), _i) #define I2bv(_f, _e) I((_f) | ByteOp, _e), I(_f, _e) #define D6ALU(_f) D2bv((_f) | DstMem | SrcReg | ModRM), \ @@ -2751,6 +2759,7 @@ done_prefixes: } c->execute = opcode.u.execute; + c->check_perm = opcode.check_perm; c->intercept = opcode.intercept; /* Unrecognised? */ @@ -2999,6 +3008,13 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) goto done; } + /* Do instruction specific permission checks */ + if (c->check_perm) { + rc = c->check_perm(ctxt); + if (rc != X86EMUL_CONTINUE) + goto done; + } + if (unlikely(ctxt->guest_mode) && c->intercept) { rc = ops->intercept(ctxt, c->intercept, X86_ICPT_POST_EXCEPT);