diff options
Diffstat (limited to 'debian/patches/bugfix/x86/retbleed/0042-KVM-VMX-Convert-launched-argument-to-flags.patch')
| -rw-r--r-- | debian/patches/bugfix/x86/retbleed/0042-KVM-VMX-Convert-launched-argument-to-flags.patch | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/debian/patches/bugfix/x86/retbleed/0042-KVM-VMX-Convert-launched-argument-to-flags.patch b/debian/patches/bugfix/x86/retbleed/0042-KVM-VMX-Convert-launched-argument-to-flags.patch new file mode 100644 index 000000000..9e04918ec --- /dev/null +++ b/debian/patches/bugfix/x86/retbleed/0042-KVM-VMX-Convert-launched-argument-to-flags.patch @@ -0,0 +1,175 @@ +From: Josh Poimboeuf <jpoimboe@kernel.org> +Date: Tue, 14 Jun 2022 23:16:12 +0200 +Subject: KVM: VMX: Convert launched argument to flags +Origin: https://git.kernel.org/linus/bb06650634d3552c0f8557e9d16aa1a408040e28 + +Convert __vmx_vcpu_run()'s 'launched' argument to 'flags', in +preparation for doing SPEC_CTRL handling immediately after vmexit, which +will need another flag. + +This is much easier than adding a fourth argument, because this code +supports both 32-bit and 64-bit, and the fourth argument on 32-bit would +have to be pushed on the stack. + +Note that __vmx_vcpu_run_flags() is called outside of the noinstr +critical section because it will soon start calling potentially +traceable functions. + +Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> +Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> +Signed-off-by: Borislav Petkov <bp@suse.de> +--- + arch/x86/kvm/vmx/nested.c | 2 +- + arch/x86/kvm/vmx/run_flags.h | 7 +++++++ + arch/x86/kvm/vmx/vmenter.S | 9 +++++---- + arch/x86/kvm/vmx/vmx.c | 17 ++++++++++++++--- + arch/x86/kvm/vmx/vmx.h | 5 ++++- + 5 files changed, 31 insertions(+), 9 deletions(-) + create mode 100644 arch/x86/kvm/vmx/run_flags.h + +diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c +index f5cb18e00e78..3a4e895269d7 100644 +--- a/arch/x86/kvm/vmx/nested.c ++++ b/arch/x86/kvm/vmx/nested.c +@@ -3087,7 +3087,7 @@ static int nested_vmx_check_vmentry_hw(struct kvm_vcpu *vcpu) + } + + vm_fail = __vmx_vcpu_run(vmx, (unsigned long *)&vcpu->arch.regs, +- vmx->loaded_vmcs->launched); ++ __vmx_vcpu_run_flags(vmx)); + + if (vmx->msr_autoload.host.nr) + vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, vmx->msr_autoload.host.nr); +diff --git a/arch/x86/kvm/vmx/run_flags.h b/arch/x86/kvm/vmx/run_flags.h +new file mode 100644 +index 000000000000..57f4c664ea9c +--- /dev/null ++++ b/arch/x86/kvm/vmx/run_flags.h +@@ -0,0 +1,7 @@ ++/* SPDX-License-Identifier: GPL-2.0 */ ++#ifndef __KVM_X86_VMX_RUN_FLAGS_H ++#define __KVM_X86_VMX_RUN_FLAGS_H ++ ++#define VMX_RUN_VMRESUME (1 << 0) ++ ++#endif /* __KVM_X86_VMX_RUN_FLAGS_H */ +diff --git a/arch/x86/kvm/vmx/vmenter.S b/arch/x86/kvm/vmx/vmenter.S +index c83163fb2e9c..ddc3bf85db33 100644 +--- a/arch/x86/kvm/vmx/vmenter.S ++++ b/arch/x86/kvm/vmx/vmenter.S +@@ -5,6 +5,7 @@ + #include <asm/kvm_vcpu_regs.h> + #include <asm/nospec-branch.h> + #include <asm/segment.h> ++#include "run_flags.h" + + #define WORD_SIZE (BITS_PER_LONG / 8) + +@@ -34,7 +35,7 @@ + * __vmx_vcpu_run - Run a vCPU via a transition to VMX guest mode + * @vmx: struct vcpu_vmx * (forwarded to vmx_update_host_rsp) + * @regs: unsigned long * (to guest registers) +- * @launched: %true if the VMCS has been launched ++ * @flags: VMX_RUN_VMRESUME: use VMRESUME instead of VMLAUNCH + * + * Returns: + * 0 on VM-Exit, 1 on VM-Fail +@@ -59,7 +60,7 @@ SYM_FUNC_START(__vmx_vcpu_run) + */ + push %_ASM_ARG2 + +- /* Copy @launched to BL, _ASM_ARG3 is volatile. */ ++ /* Copy @flags to BL, _ASM_ARG3 is volatile. */ + mov %_ASM_ARG3B, %bl + + lea (%_ASM_SP), %_ASM_ARG2 +@@ -69,7 +70,7 @@ SYM_FUNC_START(__vmx_vcpu_run) + mov (%_ASM_SP), %_ASM_AX + + /* Check if vmlaunch or vmresume is needed */ +- testb %bl, %bl ++ testb $VMX_RUN_VMRESUME, %bl + + /* Load guest registers. Don't clobber flags. */ + mov VCPU_RCX(%_ASM_AX), %_ASM_CX +@@ -92,7 +93,7 @@ SYM_FUNC_START(__vmx_vcpu_run) + mov VCPU_RAX(%_ASM_AX), %_ASM_AX + + /* Check EFLAGS.ZF from 'testb' above */ +- je .Lvmlaunch ++ jz .Lvmlaunch + + /* + * After a successful VMRESUME/VMLAUNCH, control flow "magically" +diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c +index 009bbae9ad66..b255c2a5f680 100644 +--- a/arch/x86/kvm/vmx/vmx.c ++++ b/arch/x86/kvm/vmx/vmx.c +@@ -839,6 +839,16 @@ static bool msr_write_intercepted(struct vcpu_vmx *vmx, u32 msr) + MSR_IA32_SPEC_CTRL); + } + ++unsigned int __vmx_vcpu_run_flags(struct vcpu_vmx *vmx) ++{ ++ unsigned int flags = 0; ++ ++ if (vmx->loaded_vmcs->launched) ++ flags |= VMX_RUN_VMRESUME; ++ ++ return flags; ++} ++ + static void clear_atomic_switch_msr_special(struct vcpu_vmx *vmx, + unsigned long entry, unsigned long exit) + { +@@ -6826,7 +6836,8 @@ static fastpath_t vmx_exit_handlers_fastpath(struct kvm_vcpu *vcpu) + } + + static noinstr void vmx_vcpu_enter_exit(struct kvm_vcpu *vcpu, +- struct vcpu_vmx *vmx) ++ struct vcpu_vmx *vmx, ++ unsigned long flags) + { + guest_state_enter_irqoff(); + +@@ -6845,7 +6856,7 @@ static noinstr void vmx_vcpu_enter_exit(struct kvm_vcpu *vcpu, + native_write_cr2(vcpu->arch.cr2); + + vmx->fail = __vmx_vcpu_run(vmx, (unsigned long *)&vcpu->arch.regs, +- vmx->loaded_vmcs->launched); ++ flags); + + vcpu->arch.cr2 = native_read_cr2(); + +@@ -6953,7 +6964,7 @@ static fastpath_t vmx_vcpu_run(struct kvm_vcpu *vcpu) + x86_spec_ctrl_set_guest(vmx->spec_ctrl, 0); + + /* The actual VMENTER/EXIT is in the .noinstr.text section. */ +- vmx_vcpu_enter_exit(vcpu, vmx); ++ vmx_vcpu_enter_exit(vcpu, vmx, __vmx_vcpu_run_flags(vmx)); + + /* + * We do not use IBRS in the kernel. If this vCPU has used the +diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h +index 8d2342ede0c5..1b1982448aa4 100644 +--- a/arch/x86/kvm/vmx/vmx.h ++++ b/arch/x86/kvm/vmx/vmx.h +@@ -13,6 +13,7 @@ + #include "vmcs.h" + #include "vmx_ops.h" + #include "cpuid.h" ++#include "run_flags.h" + + #define MSR_TYPE_R 1 + #define MSR_TYPE_W 2 +@@ -404,7 +405,9 @@ void vmx_set_virtual_apic_mode(struct kvm_vcpu *vcpu); + struct vmx_uret_msr *vmx_find_uret_msr(struct vcpu_vmx *vmx, u32 msr); + void pt_update_intercept_for_msr(struct kvm_vcpu *vcpu); + void vmx_update_host_rsp(struct vcpu_vmx *vmx, unsigned long host_rsp); +-bool __vmx_vcpu_run(struct vcpu_vmx *vmx, unsigned long *regs, bool launched); ++unsigned int __vmx_vcpu_run_flags(struct vcpu_vmx *vmx); ++bool __vmx_vcpu_run(struct vcpu_vmx *vmx, unsigned long *regs, ++ unsigned int flags); + int vmx_find_loadstore_msr_slot(struct vmx_msrs *m, u32 msr); + void vmx_ept_load_pdptrs(struct kvm_vcpu *vcpu); + |