| Message ID | 1456119321-10384-4-git-send-email-shuai.ruan@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
>>> On 22.02.16 at 06:35, <shuai.ruan@linux.intel.com> wrote: > --- a/xen/arch/x86/hvm/hvm.c > +++ b/xen/arch/x86/hvm/hvm.c > @@ -4703,7 +4703,19 @@ void hvm_cpuid(unsigned int input, unsigned int *eax, unsigned int *ebx, > for ( sub_leaf = 2; sub_leaf < 63; sub_leaf++ ) > if ( (v->arch.xcr0 | v->arch.hvm_vcpu.msr_xss) & > (1ULL << sub_leaf) ) > + { > + domain_cpuid(d, input, sub_leaf, &_eax, &_ebx, > + &_ecx, &_edx); > + /* > + * The value return by _ecx[1] indicates the > + * alignment of the state component i when the > + * compacted format of the extended region of > + * an xsave area is used. > + */ > + if (_ecx & XSTATE_ALIGN64) > + *ebx = ROUNDUP(*ebx, 64); > *ebx += xstate_sizes[sub_leaf]; > + } > } Besides the various coding style issues I wonder how you get away without any similar adjustment to pv_cpuid(). Jan
On Mon, Feb 22, 2016 at 10:18:42AM -0700, Jan Beulich wrote: > > @@ -4703,7 +4703,19 @@ void hvm_cpuid(unsigned int input, unsigned int *eax, unsigned int *ebx, > > for ( sub_leaf = 2; sub_leaf < 63; sub_leaf++ ) > > if ( (v->arch.xcr0 | v->arch.hvm_vcpu.msr_xss) & > > (1ULL << sub_leaf) ) > > + { > > + domain_cpuid(d, input, sub_leaf, &_eax, &_ebx, > > + &_ecx, &_edx); > > + /* > > + * The value return by _ecx[1] indicates the > > + * alignment of the state component i when the > > + * compacted format of the extended region of > > + * an xsave area is used. > > + */ > > + if (_ecx & XSTATE_ALIGN64) > > + *ebx = ROUNDUP(*ebx, 64); > > *ebx += xstate_sizes[sub_leaf]; > > + } > > } > > Besides the various coding style issues I wonder how you get > away without any similar adjustment to pv_cpuid(). Current pv does not support xsaves , and ebx return by CPUID (eax= 0xd, ecx =1 ) is depend on xcr0 | msr_xss. msr_xss is only support in hvm. Thanks > > Jan > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel >
On Mon, Feb 22, 2016 at 10:18:42AM -0700, Jan Beulich wrote: > > (1ULL << sub_leaf) ) > > + { > > + domain_cpuid(d, input, sub_leaf, &_eax, &_ebx, > > + &_ecx, &_edx); > > + /* > > + * The value return by _ecx[1] indicates the > > + * alignment of the state component i when the > > + * compacted format of the extended region of > > + * an xsave area is used. > > + */ > > + if (_ecx & XSTATE_ALIGN64) > > + *ebx = ROUNDUP(*ebx, 64); > > *ebx += xstate_sizes[sub_leaf]; > > + } > > } > > Besides the various coding style issues I wonder how you get > away without any similar adjustment to pv_cpuid(). > Please ignore the email reponse to your question earlier. I will add pv_cpuid() support too. Thanks > Jan > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel >
>>> On 24.02.16 at 06:42, <shuai.ruan@linux.intel.com> wrote: > On Mon, Feb 22, 2016 at 10:18:42AM -0700, Jan Beulich wrote: >> > @@ -4703,7 +4703,19 @@ void hvm_cpuid(unsigned int input, unsigned int *eax, > unsigned int *ebx, >> > for ( sub_leaf = 2; sub_leaf < 63; sub_leaf++ ) >> > if ( (v->arch.xcr0 | v->arch.hvm_vcpu.msr_xss) & >> > (1ULL << sub_leaf) ) >> > + { >> > + domain_cpuid(d, input, sub_leaf, &_eax, &_ebx, >> > + &_ecx, &_edx); >> > + /* >> > + * The value return by _ecx[1] indicates the >> > + * alignment of the state component i when the >> > + * compacted format of the extended region of >> > + * an xsave area is used. >> > + */ >> > + if (_ecx & XSTATE_ALIGN64) >> > + *ebx = ROUNDUP(*ebx, 64); >> > *ebx += xstate_sizes[sub_leaf]; >> > + } >> > } >> >> Besides the various coding style issues I wonder how you get >> away without any similar adjustment to pv_cpuid(). > Current pv does not support xsaves , and ebx return by CPUID (eax= 0xd, > ecx =1 ) is depend on xcr0 | msr_xss. msr_xss is only support in hvm. My reading of the manual didn't result in such a connection. Mind pointing out where this is being stated? (From an abstract perspective I also can't see why the alignment flag would be tied to XSAVES.) Jan
diff --git a/tools/libxc/xc_cpuid_x86.c b/tools/libxc/xc_cpuid_x86.c index c142595..d36f20b 100644 --- a/tools/libxc/xc_cpuid_x86.c +++ b/tools/libxc/xc_cpuid_x86.c @@ -285,6 +285,7 @@ static void intel_xc_cpuid_policy(xc_interface *xch, #define XSAVEC (1 << 1) #define XGETBV1 (1 << 2) #define XSAVES (1 << 3) +#define XSTATE_ALIGN64 (1 << 1) /* Configure extended state enumeration leaves (0x0000000D for xsave) */ static void xc_cpuid_config_xsave(xc_interface *xch, const struct cpuid_domain_info *info, @@ -333,8 +334,13 @@ static void xc_cpuid_config_xsave(xc_interface *xch, regs[0] = regs[1] = regs[2] = regs[3] = 0; break; } - /* Don't touch EAX, EBX. Also cleanup ECX and EDX */ - regs[2] = regs[3] = 0; + /* Don't touch EAX, EBX. + * ECX[1] indicates whether the state component + * needs alignment when compacted format is used. + */ + regs[2] &= XSTATE_ALIGN64; + /* Clean up EDX */ + regs[3] = 0; break; } } diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c index fe382ce..4ccd392 100644 --- a/xen/arch/x86/hvm/hvm.c +++ b/xen/arch/x86/hvm/hvm.c @@ -4703,7 +4703,19 @@ void hvm_cpuid(unsigned int input, unsigned int *eax, unsigned int *ebx, for ( sub_leaf = 2; sub_leaf < 63; sub_leaf++ ) if ( (v->arch.xcr0 | v->arch.hvm_vcpu.msr_xss) & (1ULL << sub_leaf) ) + { + domain_cpuid(d, input, sub_leaf, &_eax, &_ebx, + &_ecx, &_edx); + /* + * The value return by _ecx[1] indicates the + * alignment of the state component i when the + * compacted format of the extended region of + * an xsave area is used. + */ + if (_ecx & XSTATE_ALIGN64) + *ebx = ROUNDUP(*ebx, 64); *ebx += xstate_sizes[sub_leaf]; + } } else *ebx = *ecx = *edx = 0;
Refer to SDM 13.4.3 Extended Region of an XSAVE Area. The value return by ecx[1] with cpuid function 0xdh and sub-fucntion i (i>1) indicates the alignment of the state component i when the compacted format of the extended region of an xsave area is used. So when hvm guest using CPUID eax=0xdh,ecx=1 to get the size of area used for compacted format, we need to take alignment into consideration. Signed-off-by: Shuai Ruan <shuai.ruan@linux.intel.com> --- tools/libxc/xc_cpuid_x86.c | 10 ++++++++-- xen/arch/x86/hvm/hvm.c | 12 ++++++++++++ 2 files changed, 20 insertions(+), 2 deletions(-)