Commit decddf55 authored by Josh Poimboeuf's avatar Josh Poimboeuf Committed by Zheng Zengkai
Browse files

KVM: VMX: Convert launched argument to flags 

stable inclusion
from stable-v5.10.133
commit 84061fff2ad98a7809f00e88a54f584f84830388
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5PTAS
CVE: CVE-2022-29900,CVE-2022-23816,CVE-2022-29901

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=84061fff2ad98a7809f00e88a54f584f84830388



--------------------------------

commit bb066506 upstream.

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: default avatarJosh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarThadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>

conflict:
	arch/x86/kvm/vmx/vmx.h

Signed-off-by: default avatarLin Yujun <linyujun809@huawei.com>
Reviewed-by: default avatarZhang Jianhua <chris.zjh@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent 1db122e4

arch/x86/kvm/vmx/nested.c

+1 −1
Original line number Diff line number Diff line
@@ -3081,7 +3081,7 @@ 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);

arch/x86/kvm/vmx/run_flags.h

0 → 100644
+7 −0
Original line number Diff line number Diff line 
/* 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 */

arch/x86/kvm/vmx/vmenter.S

+5 −4
Original line number Diff line number Diff line
@@ -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"

arch/x86/kvm/vmx/vmx.c

+14 −3
Original line number Diff line number Diff line
@@ -945,6 +945,16 @@ static bool msr_write_intercepted(struct vcpu_vmx *vmx, u32 msr) 
	return true;

}



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)

{
@@ -6818,7 +6828,8 @@ 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)

{

	/*

	 * VMENTER enables interrupts (host state), but the kernel state is
@@ -6855,7 +6866,7 @@ 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();
@@ -6956,7 +6967,7 @@ 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

arch/x86/kvm/vmx/vmx.h

+4 −1
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include "vmcs.h"

#include "vmx_ops.h"

#include "cpuid.h"

#include "run_flags.h"



extern const u32 vmx_msr_index[];
@@ -394,7 +395,9 @@ 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);

void vmx_set_intercept_for_msr(struct kvm_vcpu *vcpu,