From 60bb1d8cd45c041117a65374478e8da7d8e23f60 Mon Sep 17 00:00:00 2001 From: Shan Haitao Date: Sun, 18 Sep 2011 00:01:58 +0100 Subject: [PATCH] Fix PV CPUID virtualization of XSave The patch will fix XSave CPUID virtualization for PV guests. The XSave area size returned by CPUID leaf D is changed dynamically depending on the XCR0. Tools/libxc only assigns a static value. The fix will adjust xsave area size during runtime. Note: This fix is already in HVM cpuid virtualization. And Dom0 is not affected, either. Signed-off-by: Shan Haitao --- xen/arch/x86/hvm/hvm.c | 2 +- xen/arch/x86/traps.c | 24 ++++++++++++++++++++++++ 2 files changed, 25 insertions(+), 1 deletion(-) diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c index bce2df8d0a..b8225e6b98 100644 --- a/xen/arch/x86/hvm/hvm.c +++ b/xen/arch/x86/hvm/hvm.c @@ -2426,7 +2426,7 @@ void hvm_cpuid(unsigned int input, unsigned int *eax, unsigned int *ebx, { /* reset EBX to default value first */ *ebx = XSTATE_AREA_MIN_SIZE; - for ( sub_leaf = 2; sub_leaf < 64; sub_leaf++ ) + for ( sub_leaf = 2; sub_leaf < 63; sub_leaf++ ) { if ( !(v->arch.xcr0 & (1ULL << sub_leaf)) ) continue; diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c index 183ce91b74..0203613b53 100644 --- a/xen/arch/x86/traps.c +++ b/xen/arch/x86/traps.c @@ -770,6 +770,30 @@ static void pv_cpuid(struct cpu_user_regs *regs) { if ( !cpuid_hypervisor_leaves(a, c, &a, &b, &c, &d) ) domain_cpuid(current->domain, a, c, &a, &b, &c, &d); + + switch ( a ) + { + case 0xd: + { + unsigned int sub_leaf, _eax, _ebx, _ecx, _edx; + /* EBX value of main leaf 0 depends on enabled xsave features */ + if ( c == 0 && current->arch.xcr0 ) + { + /* reset EBX to default value first */ + b = XSTATE_AREA_MIN_SIZE; + for ( sub_leaf = 2; sub_leaf < 63; sub_leaf++ ) + { + if ( !(current->arch.xcr0 & (1ULL << sub_leaf)) ) + continue; + domain_cpuid(current->domain, a, c, &_eax, &_ebx, &_ecx, + &_edx); + if ( (_eax + _ebx) > b ) + b = _eax + _ebx; + } + } + break; + } + } goto out; } -- 2.30.2