From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boris Ostrovsky Subject: Re: [PATCH v4 4/4] x86: make hvm_cpuid() tolerate NULL pointers Date: Mon, 23 Sep 2013 09:42:44 -0400 Message-ID: <52404554.1070200@oracle.com> References: <52402E3202000078000F5665@nat28.tlf.novell.com> <5240304502000078000F570D@nat28.tlf.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1VO6Nb-00011g-Nh for xen-devel@lists.xenproject.org; Mon, 23 Sep 2013 13:40:48 +0000 In-Reply-To: <5240304502000078000F570D@nat28.tlf.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich Cc: Keir Fraser , suravee.suthikulpanit@amd.com, Eddie Dong , Jacob Shin , Jun Nakajima , Yang Z Zhang , xen-devel List-Id: xen-devel@lists.xenproject.org On 09/23/2013 06:12 AM, Jan Beulich wrote: > Now that we other HVM code start making more extensive use of Something is wrong with this sentence. I think "we" is not needed. Other than that Acked-by: Boris Ostrovsky -boris > hvm_cpuid(), let's not force every caller to declare dummy variables > for output not cared about. > > Signed-off-by: Jan Beulich > > --- a/xen/arch/x86/hvm/hvm.c > +++ b/xen/arch/x86/hvm/hvm.c > @@ -2757,7 +2757,17 @@ void hvm_cpuid(unsigned int input, unsig > { > struct vcpu *v = current; > struct domain *d = v->domain; > - unsigned int count = *ecx; > + unsigned int count, dummy = 0; > + > + if ( !eax ) > + eax = &dummy; > + if ( !ebx ) > + ebx = &dummy; > + if ( !ecx ) > + ecx = &dummy; > + count = *ecx; > + if ( !edx ) > + edx = &dummy; > > if ( cpuid_viridian_leaves(input, eax, ebx, ecx, edx) ) > return; > @@ -2765,7 +2775,7 @@ void hvm_cpuid(unsigned int input, unsig > if ( cpuid_hypervisor_leaves(input, count, eax, ebx, ecx, edx) ) > return; > > - domain_cpuid(d, input, *ecx, eax, ebx, ecx, edx); > + domain_cpuid(d, input, count, eax, ebx, ecx, edx); > > switch ( input ) > { > @@ -2853,15 +2863,15 @@ int hvm_msr_read_intercept(unsigned int > { > struct vcpu *v = current; > uint64_t *var_range_base, *fixed_range_base; > - int index, mtrr; > - uint32_t cpuid[4]; > + bool_t mtrr; > + unsigned int edx, index; > int ret = X86EMUL_OKAY; > > var_range_base = (uint64_t *)v->arch.hvm_vcpu.mtrr.var_ranges; > fixed_range_base = (uint64_t *)v->arch.hvm_vcpu.mtrr.fixed_ranges; > > - hvm_cpuid(1, &cpuid[0], &cpuid[1], &cpuid[2], &cpuid[3]); > - mtrr = !!(cpuid[3] & cpufeat_mask(X86_FEATURE_MTRR)); > + hvm_cpuid(1, NULL, NULL, NULL, &edx); > + mtrr = !!(edx & cpufeat_mask(X86_FEATURE_MTRR)); > > switch ( msr ) > { > @@ -2969,15 +2979,15 @@ int hvm_msr_read_intercept(unsigned int > int hvm_msr_write_intercept(unsigned int msr, uint64_t msr_content) > { > struct vcpu *v = current; > - int index, mtrr; > - uint32_t cpuid[4]; > + bool_t mtrr; > + unsigned int edx, index; > int ret = X86EMUL_OKAY; > > HVMTRACE_3D(MSR_WRITE, msr, > (uint32_t)msr_content, (uint32_t)(msr_content >> 32)); > > - hvm_cpuid(1, &cpuid[0], &cpuid[1], &cpuid[2], &cpuid[3]); > - mtrr = !!(cpuid[3] & cpufeat_mask(X86_FEATURE_MTRR)); > + hvm_cpuid(1, NULL, NULL, NULL, &edx); > + mtrr = !!(edx & cpufeat_mask(X86_FEATURE_MTRR)); > > hvm_memory_event_msr(msr, msr_content); > > --- a/xen/arch/x86/hvm/svm/svm.c > +++ b/xen/arch/x86/hvm/svm/svm.c > @@ -806,13 +806,13 @@ static inline void svm_lwp_load(struct v > /* Update LWP_CFG MSR (0xc0000105). Return -1 if error; otherwise returns 0. */ > static int svm_update_lwp_cfg(struct vcpu *v, uint64_t msr_content) > { > - unsigned int eax, ebx, ecx, edx; > + unsigned int edx; > uint32_t msr_low; > static uint8_t lwp_intr_vector; > > if ( xsave_enabled(v) && cpu_has_lwp ) > { > - hvm_cpuid(0x8000001c, &eax, &ebx, &ecx, &edx); > + hvm_cpuid(0x8000001c, NULL, NULL, NULL, &edx); > msr_low = (uint32_t)msr_content; > > /* generate #GP if guest tries to turn on unsupported features. */ > @@ -1163,10 +1163,10 @@ static void svm_init_erratum_383(struct > > static int svm_handle_osvw(struct vcpu *v, uint32_t msr, uint64_t *val, bool_t read) > { > - uint eax, ebx, ecx, edx; > + unsigned int ecx; > > /* Guest OSVW support */ > - hvm_cpuid(0x80000001, &eax, &ebx, &ecx, &edx); > + hvm_cpuid(0x80000001, NULL, NULL, &ecx, NULL); > if ( !test_bit((X86_FEATURE_OSVW & 31), &ecx) ) > return -1; > > --- a/xen/arch/x86/hvm/vmx/vvmx.c > +++ b/xen/arch/x86/hvm/vmx/vvmx.c > @@ -1813,7 +1813,7 @@ int nvmx_handle_invvpid(struct cpu_user_ > int nvmx_msr_read_intercept(unsigned int msr, u64 *msr_content) > { > struct vcpu *v = current; > - unsigned int eax, ebx, ecx, edx, dummy; > + unsigned int eax, ebx, ecx, edx; > u64 data = 0, host_data = 0; > int r = 1; > > @@ -1821,7 +1821,7 @@ int nvmx_msr_read_intercept(unsigned int > return 0; > > /* VMX capablity MSRs are available only when guest supports VMX. */ > - hvm_cpuid(0x1, &dummy, &dummy, &ecx, &edx); > + hvm_cpuid(0x1, NULL, NULL, &ecx, &edx); > if ( !(ecx & cpufeat_mask(X86_FEATURE_VMXE)) ) > return 0; > > @@ -1972,18 +1972,18 @@ int nvmx_msr_read_intercept(unsigned int > if ( ecx & cpufeat_mask(X86_FEATURE_XSAVE) ) > data |= X86_CR4_OSXSAVE; > > - hvm_cpuid(0x0, &eax, &dummy, &dummy, &dummy); > + hvm_cpuid(0x0, &eax, NULL, NULL, NULL); > switch ( eax ) > { > default: > - hvm_cpuid(0xa, &eax, &dummy, &dummy, &dummy); > + hvm_cpuid(0xa, &eax, NULL, NULL, NULL); > /* Check whether guest has the perf monitor feature. */ > if ( (eax & 0xff) && (eax & 0xff00) ) > data |= X86_CR4_PCE; > /* fall through */ > case 0x7 ... 0x9: > ecx = 0; > - hvm_cpuid(0x7, &dummy, &ebx, &ecx, &dummy); > + hvm_cpuid(0x7, NULL, &ebx, &ecx, NULL); > if ( ebx & cpufeat_mask(X86_FEATURE_FSGSBASE) ) > data |= X86_CR4_FSGSBASE; > if ( ebx & cpufeat_mask(X86_FEATURE_SMEP) ) > >