diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2019-11-11 23:03:18 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2019-11-16 11:24:00 +0100 |
| commit | 6b546e1c9ad2a25f874f8bc6077d0f55f9446414 (patch) | |
| tree | 86a938e9727f3cc7e5a8c8a135de3d70bc04b78d | |
| parent | 505b789996f64bdbfcc5847dd4b5076fc7c50274 (diff) | |
x86/tss: Fix and move VMX BUILD_BUG_ON()
The BUILD_BUG_ON(IO_BITMAP_OFFSET - 1 == 0x67) in the VMX code is bogus in
two aspects:
1) This wants to be in generic x86 code simply to catch issues even when
VMX is disabled in Kconfig.
2) The IO_BITMAP_OFFSET is not the right thing to check because it makes
asssumptions about the layout of tss_struct. Nothing requires that the
I/O bitmap is placed right after x86_tss, which is the hardware mandated
tss structure. It pointlessly makes restrictions on the struct
tss_struct layout.
The proper thing to check is:
- Offset of x86_tss in tss_struct is 0
- Size of x86_tss == 0x68
Move it to the other build time TSS checks and make it do the right thing.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 8 | ||||
| -rw-r--r-- | arch/x86/mm/cpu_entry_area.c | 8 |
2 files changed, 8 insertions, 8 deletions
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 5d21a4ab28cf..311fd48d99e2 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -1338,14 +1338,6 @@ void vmx_vcpu_load_vmcs(struct kvm_vcpu *vcpu, int cpu) (unsigned long)&get_cpu_entry_area(cpu)->tss.x86_tss); vmcs_writel(HOST_GDTR_BASE, (unsigned long)gdt); /* 22.2.4 */ - /* - * VM exits change the host TR limit to 0x67 after a VM - * exit. This is okay, since 0x67 covers everything except - * the IO bitmap and have have code to handle the IO bitmap - * being lost after a VM exit. - */ - BUILD_BUG_ON(IO_BITMAP_OFFSET - 1 != 0x67); - rdmsrl(MSR_IA32_SYSENTER_ESP, sysenter_esp); vmcs_writel(HOST_IA32_SYSENTER_ESP, sysenter_esp); /* 22.2.3 */ diff --git a/arch/x86/mm/cpu_entry_area.c b/arch/x86/mm/cpu_entry_area.c index 752ad11d6868..2c1d4223a343 100644 --- a/arch/x86/mm/cpu_entry_area.c +++ b/arch/x86/mm/cpu_entry_area.c @@ -161,6 +161,14 @@ static void __init setup_cpu_entry_area(unsigned int cpu) BUILD_BUG_ON((offsetof(struct tss_struct, x86_tss) ^ offsetofend(struct tss_struct, x86_tss)) & PAGE_MASK); BUILD_BUG_ON(sizeof(struct tss_struct) % PAGE_SIZE != 0); + /* + * VMX changes the host TR limit to 0x67 after a VM exit. This is + * okay, since 0x67 covers the size of struct x86_hw_tss. Make sure + * that this is correct. + */ + BUILD_BUG_ON(offsetof(struct tss_struct, x86_tss) != 0); + BUILD_BUG_ON(sizeof(struct x86_hw_tss) != 0x68); + cea_map_percpu_pages(&cea->tss, &per_cpu(cpu_tss_rw, cpu), sizeof(struct tss_struct) / PAGE_SIZE, tss_prot); |