diff options
Diffstat (limited to 'arch/x86/kernel/paravirt_patch.c')
| -rw-r--r-- | arch/x86/kernel/paravirt_patch.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/arch/x86/kernel/paravirt_patch.c b/arch/x86/kernel/paravirt_patch.c new file mode 100644 index 000000000000..3eff63c090d2 --- /dev/null +++ b/arch/x86/kernel/paravirt_patch.c @@ -0,0 +1,126 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/stringify.h> + +#include <asm/paravirt.h> +#include <asm/asm-offsets.h> + +#define PSTART(d, m) \ + patch_data_##d.m + +#define PEND(d, m) \ + (PSTART(d, m) + sizeof(patch_data_##d.m)) + +#define PATCH(d, m, insn_buff, len) \ + paravirt_patch_insns(insn_buff, len, PSTART(d, m), PEND(d, m)) + +#define PATCH_CASE(ops, m, data, insn_buff, len) \ + case PARAVIRT_PATCH(ops.m): \ + return PATCH(data, ops##_##m, insn_buff, len) + +#ifdef CONFIG_PARAVIRT_XXL +struct patch_xxl { + const unsigned char irq_irq_disable[1]; + const unsigned char irq_irq_enable[1]; + const unsigned char irq_save_fl[2]; + const unsigned char mmu_read_cr2[3]; + const unsigned char mmu_read_cr3[3]; + const unsigned char mmu_write_cr3[3]; + const unsigned char irq_restore_fl[2]; +# ifdef CONFIG_X86_64 + const unsigned char cpu_wbinvd[2]; + const unsigned char cpu_usergs_sysret64[6]; + const unsigned char cpu_swapgs[3]; + const unsigned char mov64[3]; +# else + const unsigned char cpu_iret[1]; +# endif +}; + +static const struct patch_xxl patch_data_xxl = { + .irq_irq_disable = { 0xfa }, // cli + .irq_irq_enable = { 0xfb }, // sti + .irq_save_fl = { 0x9c, 0x58 }, // pushf; pop %[re]ax + .mmu_read_cr2 = { 0x0f, 0x20, 0xd0 }, // mov %cr2, %[re]ax + .mmu_read_cr3 = { 0x0f, 0x20, 0xd8 }, // mov %cr3, %[re]ax +# ifdef CONFIG_X86_64 + .mmu_write_cr3 = { 0x0f, 0x22, 0xdf }, // mov %rdi, %cr3 + .irq_restore_fl = { 0x57, 0x9d }, // push %rdi; popfq + .cpu_wbinvd = { 0x0f, 0x09 }, // wbinvd + .cpu_usergs_sysret64 = { 0x0f, 0x01, 0xf8, + 0x48, 0x0f, 0x07 }, // swapgs; sysretq + .cpu_swapgs = { 0x0f, 0x01, 0xf8 }, // swapgs + .mov64 = { 0x48, 0x89, 0xf8 }, // mov %rdi, %rax +# else + .mmu_write_cr3 = { 0x0f, 0x22, 0xd8 }, // mov %eax, %cr3 + .irq_restore_fl = { 0x50, 0x9d }, // push %eax; popf + .cpu_iret = { 0xcf }, // iret +# endif +}; + +unsigned int paravirt_patch_ident_64(void *insn_buff, unsigned int len) +{ +#ifdef CONFIG_X86_64 + return PATCH(xxl, mov64, insn_buff, len); +#endif + return 0; +} +# endif /* CONFIG_PARAVIRT_XXL */ + +#ifdef CONFIG_PARAVIRT_SPINLOCKS +struct patch_lock { + unsigned char queued_spin_unlock[3]; + unsigned char vcpu_is_preempted[2]; +}; + +static const struct patch_lock patch_data_lock = { + .vcpu_is_preempted = { 0x31, 0xc0 }, // xor %eax, %eax + +# ifdef CONFIG_X86_64 + .queued_spin_unlock = { 0xc6, 0x07, 0x00 }, // movb $0, (%rdi) +# else + .queued_spin_unlock = { 0xc6, 0x00, 0x00 }, // movb $0, (%eax) +# endif +}; +#endif /* CONFIG_PARAVIRT_SPINLOCKS */ + +unsigned int native_patch(u8 type, void *insn_buff, unsigned long addr, + unsigned int len) +{ + switch (type) { + +#ifdef CONFIG_PARAVIRT_XXL + PATCH_CASE(irq, restore_fl, xxl, insn_buff, len); + PATCH_CASE(irq, save_fl, xxl, insn_buff, len); + PATCH_CASE(irq, irq_enable, xxl, insn_buff, len); + PATCH_CASE(irq, irq_disable, xxl, insn_buff, len); + + PATCH_CASE(mmu, read_cr2, xxl, insn_buff, len); + PATCH_CASE(mmu, read_cr3, xxl, insn_buff, len); + PATCH_CASE(mmu, write_cr3, xxl, insn_buff, len); + +# ifdef CONFIG_X86_64 + PATCH_CASE(cpu, usergs_sysret64, xxl, insn_buff, len); + PATCH_CASE(cpu, swapgs, xxl, insn_buff, len); + PATCH_CASE(cpu, wbinvd, xxl, insn_buff, len); +# else + PATCH_CASE(cpu, iret, xxl, insn_buff, len); +# endif +#endif + +#ifdef CONFIG_PARAVIRT_SPINLOCKS + case PARAVIRT_PATCH(lock.queued_spin_unlock): + if (pv_is_native_spin_unlock()) + return PATCH(lock, queued_spin_unlock, insn_buff, len); + break; + + case PARAVIRT_PATCH(lock.vcpu_is_preempted): + if (pv_is_native_vcpu_is_preempted()) + return PATCH(lock, vcpu_is_preempted, insn_buff, len); + break; +#endif + default: + break; + } + + return paravirt_patch_default(type, insn_buff, addr, len); +} |