From: Yang, Sheng Date: Sun, 29 Jul 2007 08:07:42 +0000 (+0300) Subject: KVM: VMX: Improve the method of writing vmcs control X-Git-Tag: firefly_0821_release~25981^2~79 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=1c3d14fe0ab75337a3f6c06b6bc18bcbc2b3d0bc;p=firefly-linux-kernel-4.4.55.git KVM: VMX: Improve the method of writing vmcs control Put cpu feature detecting part in hardware_setup, and stored the vmcs condition in global variable for further check. [glommer: fix for some i386-only machines not supporting CR8 load/store exiting] Signed-off-by: Sheng Yang Signed-off-by: Glauber de Oliveira Costa Signed-off-by: Avi Kivity --- diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c index df5787823309..18f9b0b3fb1f 100644 --- a/drivers/kvm/vmx.c +++ b/drivers/kvm/vmx.c @@ -71,18 +71,17 @@ static DEFINE_PER_CPU(struct vmcs *, current_vmcs); static struct page *vmx_io_bitmap_a; static struct page *vmx_io_bitmap_b; -#ifdef CONFIG_X86_64 -#define HOST_IS_64 1 -#else -#define HOST_IS_64 0 -#endif #define EFER_SAVE_RESTORE_BITS ((u64)EFER_SCE) -static struct vmcs_descriptor { +static struct vmcs_config { int size; int order; u32 revision_id; -} vmcs_descriptor; + u32 pin_based_exec_ctrl; + u32 cpu_based_exec_ctrl; + u32 vmexit_ctrl; + u32 vmentry_ctrl; +} vmcs_config; #define VMX_SEGMENT_FIELD(seg) \ [VCPU_SREG_##seg] = { \ @@ -839,14 +838,93 @@ static void hardware_disable(void *garbage) asm volatile (ASM_VMX_VMXOFF : : : "cc"); } -static __init void setup_vmcs_descriptor(void) +static __init int adjust_vmx_controls(u32 ctl_min, u32 ctl_opt, + u32 msr, u32* result) +{ + u32 vmx_msr_low, vmx_msr_high; + u32 ctl = ctl_min | ctl_opt; + + rdmsr(msr, vmx_msr_low, vmx_msr_high); + + ctl &= vmx_msr_high; /* bit == 0 in high word ==> must be zero */ + ctl |= vmx_msr_low; /* bit == 1 in low word ==> must be one */ + + /* Ensure minimum (required) set of control bits are supported. */ + if (ctl_min & ~ctl) + return -1; + + *result = ctl; + return 0; +} + +static __init int setup_vmcs_config(void) { u32 vmx_msr_low, vmx_msr_high; + u32 min, opt; + u32 _pin_based_exec_control = 0; + u32 _cpu_based_exec_control = 0; + u32 _vmexit_control = 0; + u32 _vmentry_control = 0; + + min = PIN_BASED_EXT_INTR_MASK | PIN_BASED_NMI_EXITING; + opt = 0; + if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_PINBASED_CTLS, + &_pin_based_exec_control) < 0) + return -1; + + min = CPU_BASED_HLT_EXITING | +#ifdef CONFIG_X86_64 + CPU_BASED_CR8_LOAD_EXITING | + CPU_BASED_CR8_STORE_EXITING | +#endif + CPU_BASED_USE_IO_BITMAPS | + CPU_BASED_MOV_DR_EXITING | + CPU_BASED_USE_TSC_OFFSETING; + opt = 0; + if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_PROCBASED_CTLS, + &_cpu_based_exec_control) < 0) + return -1; + + min = 0; +#ifdef CONFIG_X86_64 + min |= VM_EXIT_HOST_ADDR_SPACE_SIZE; +#endif + opt = 0; + if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_EXIT_CTLS, + &_vmexit_control) < 0) + return -1; + + min = opt = 0; + if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_ENTRY_CTLS, + &_vmentry_control) < 0) + return -1; rdmsr(MSR_IA32_VMX_BASIC, vmx_msr_low, vmx_msr_high); - vmcs_descriptor.size = vmx_msr_high & 0x1fff; - vmcs_descriptor.order = get_order(vmcs_descriptor.size); - vmcs_descriptor.revision_id = vmx_msr_low; + + /* IA-32 SDM Vol 3B: VMCS size is never greater than 4kB. */ + if ((vmx_msr_high & 0x1fff) > PAGE_SIZE) + return -1; + +#ifdef CONFIG_X86_64 + /* IA-32 SDM Vol 3B: 64-bit CPUs always have VMX_BASIC_MSR[48]==0. */ + if (vmx_msr_high & (1u<<16)) + return -1; +#endif + + /* Require Write-Back (WB) memory type for VMCS accesses. */ + if (((vmx_msr_high >> 18) & 15) != 6) + return -1; + + vmcs_config.size = vmx_msr_high & 0x1fff; + vmcs_config.order = get_order(vmcs_config.size); + vmcs_config.revision_id = vmx_msr_low; + + vmcs_config.pin_based_exec_ctrl = _pin_based_exec_control; + vmcs_config.cpu_based_exec_ctrl = _cpu_based_exec_control; + vmcs_config.vmexit_ctrl = _vmexit_control; + vmcs_config.vmentry_ctrl = _vmentry_control; + + return 0; } static struct vmcs *alloc_vmcs_cpu(int cpu) @@ -855,12 +933,12 @@ static struct vmcs *alloc_vmcs_cpu(int cpu) struct page *pages; struct vmcs *vmcs; - pages = alloc_pages_node(node, GFP_KERNEL, vmcs_descriptor.order); + pages = alloc_pages_node(node, GFP_KERNEL, vmcs_config.order); if (!pages) return NULL; vmcs = page_address(pages); - memset(vmcs, 0, vmcs_descriptor.size); - vmcs->revision_id = vmcs_descriptor.revision_id; /* vmcs revision id */ + memset(vmcs, 0, vmcs_config.size); + vmcs->revision_id = vmcs_config.revision_id; /* vmcs revision id */ return vmcs; } @@ -871,7 +949,7 @@ static struct vmcs *alloc_vmcs(void) static void free_vmcs(struct vmcs *vmcs) { - free_pages((unsigned long)vmcs, vmcs_descriptor.order); + free_pages((unsigned long)vmcs, vmcs_config.order); } static void free_kvm_area(void) @@ -904,7 +982,8 @@ static __init int alloc_kvm_area(void) static __init int hardware_setup(void) { - setup_vmcs_descriptor(); + if (setup_vmcs_config() < 0) + return -1; return alloc_kvm_area(); } @@ -1275,17 +1354,6 @@ static int init_rmode_tss(struct kvm* kvm) return 1; } -static void vmcs_write32_fixedbits(u32 msr, u32 vmcs_field, u32 val) -{ - u32 msr_high, msr_low; - - rdmsr(msr, msr_low, msr_high); - - val &= msr_high; - val |= msr_low; - vmcs_write32(vmcs_field, val); -} - static void seg_setup(int seg) { struct kvm_vmx_segment_field *sf = &kvm_vmx_segment_fields[seg]; @@ -1382,20 +1450,10 @@ static int vmx_vcpu_setup(struct kvm_vcpu *vcpu) vmcs_write64(GUEST_IA32_DEBUGCTL, 0); /* Control */ - vmcs_write32_fixedbits(MSR_IA32_VMX_PINBASED_CTLS, - PIN_BASED_VM_EXEC_CONTROL, - PIN_BASED_EXT_INTR_MASK /* 20.6.1 */ - | PIN_BASED_NMI_EXITING /* 20.6.1 */ - ); - vmcs_write32_fixedbits(MSR_IA32_VMX_PROCBASED_CTLS, - CPU_BASED_VM_EXEC_CONTROL, - CPU_BASED_HLT_EXITING /* 20.6.2 */ - | CPU_BASED_CR8_LOAD_EXITING /* 20.6.2 */ - | CPU_BASED_CR8_STORE_EXITING /* 20.6.2 */ - | CPU_BASED_USE_IO_BITMAPS /* 20.6.2 */ - | CPU_BASED_MOV_DR_EXITING - | CPU_BASED_USE_TSC_OFFSETING /* 21.3 */ - ); + vmcs_write32(PIN_BASED_VM_EXEC_CONTROL, + vmcs_config.pin_based_exec_ctrl); + vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, + vmcs_config.cpu_based_exec_ctrl); vmcs_write32(PAGE_FAULT_ERROR_CODE_MASK, 0); vmcs_write32(PAGE_FAULT_ERROR_CODE_MATCH, 0); @@ -1459,12 +1517,11 @@ static int vmx_vcpu_setup(struct kvm_vcpu *vcpu) setup_msrs(vcpu); - vmcs_write32_fixedbits(MSR_IA32_VMX_EXIT_CTLS, VM_EXIT_CONTROLS, - (HOST_IS_64 << 9)); /* 22.2,1, 20.7.1 */ + vmcs_write32(VM_EXIT_CONTROLS, vmcs_config.vmexit_ctrl); /* 22.2.1, 20.8.1 */ - vmcs_write32_fixedbits(MSR_IA32_VMX_ENTRY_CTLS, - VM_ENTRY_CONTROLS, 0); + vmcs_write32(VM_ENTRY_CONTROLS, vmcs_config.vmentry_ctrl); + vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, 0); /* 22.2.1 */ #ifdef CONFIG_X86_64