search for: lretq

...%rax > + movq %rax, boot_gdt_base(%rip) > + lgdt boot_gdt_descr(%rip) > + > + /* GDT loaded - switch to __KERNEL_CS so IRET works reliably */ > + pushq $__KERNEL_CS > + leaq .Lon_kernel_cs(%rip), %rax > + pushq %rax > + lretq > + > +.Lon_kernel_cs: > + UNWIND_HINT_EMPTY I would suggest fixing at least SS as well.

...b/arch/x86/boot/compressed/head_64.S > @@ -393,6 +393,14 @@ SYM_CODE_START(startup_64) > addq %rax, 2(%rax) > lgdt (%rax) > > + /* Reload CS so IRET returns to a CS actually in the GDT */ > + pushq $__KERNEL_CS > + leaq .Lon_kernel_cs(%rip), %rax > + pushq %rax > + lretq > + > +.Lon_kernel_cs: > + > /* > * paging_prepare() sets up the trampoline and checks if we need to > * enable 5-level paging. > -- So I'm thinking I should take this one even now on the grounds that it sanitizes CS to something known-good than what was there bef...

...TREGS)(%rip), %rsp + /* Setup boot GDT descriptor and load boot GDT */ + leaq boot_gdt(%rip), %rax + movq %rax, boot_gdt_base(%rip) + lgdt boot_gdt_descr(%rip) + + /* GDT loaded - switch to __KERNEL_CS so IRET works reliably */ + pushq $__KERNEL_CS + leaq .Lon_kernel_cs(%rip), %rax + pushq %rax + lretq + +.Lon_kernel_cs: + UNWIND_HINT_EMPTY + /* Sanitize CPU configuration */ call verify_cpu @@ -480,6 +494,18 @@ SYM_DATA_LOCAL(early_gdt_descr_base, .quad INIT_PER_CPU_VAR(gdt_page)) SYM_DATA(phys_base, .quad 0x0) EXPORT_SYMBOL(phys_base) +/* Boot GDT used when kernel addresses are not map...

...--- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -393,6 +393,14 @@ SYM_CODE_START(startup_64) addq %rax, 2(%rax) lgdt (%rax) + /* Reload CS so IRET returns to a CS actually in the GDT */ + pushq $__KERNEL_CS + leaq .Lon_kernel_cs(%rip), %rax + pushq %rax + lretq + +.Lon_kernel_cs: + /* * paging_prepare() sets up the trampoline and checks if we need to * enable 5-level paging. -- 2.17.1

...e(%rip) + lgdt boot_gdt_descr(%rip) + + /* New GDT is live - reload data segment registers */ + movl $__KERNEL_DS, %eax + movl %eax, %ds + movl %eax, %ss + movl %eax, %es + + /* Now switch to __KERNEL_CS so IRET works reliably */ + pushq $__KERNEL_CS + leaq .Lon_kernel_cs(%rip), %rax + pushq %rax + lretq + +.Lon_kernel_cs: + UNWIND_HINT_EMPTY + /* Sanitize CPU configuration */ call verify_cpu @@ -480,6 +500,22 @@ SYM_DATA_LOCAL(early_gdt_descr_base, .quad INIT_PER_CPU_VAR(gdt_page)) SYM_DATA(phys_base, .quad 0x0) EXPORT_SYMBOL(phys_base) +/* Boot GDT used when kernel addresses are not map...

...2(%rip) + lgdt boot_gdt_descr(%rip) + + /* New GDT is live - reload data segment registers */ + movl $__KERNEL_DS, %eax + movl %eax, %ds + movl %eax, %ss + movl %eax, %es + + /* Now switch to __KERNEL_CS so IRET works reliably */ + pushq $__KERNEL_CS + leaq .Lon_kernel_cs(%rip), %rax + pushq %rax + lretq + +.Lon_kernel_cs: + UNWIND_HINT_EMPTY + /* Sanitize CPU configuration */ call verify_cpu @@ -143,6 +163,11 @@ SYM_CODE_START(secondary_startup_64) 1: UNWIND_HINT_EMPTY + /* Setup boot GDT descriptor and load boot GDT */ + leaq boot_gdt(%rip), %rax + movq %rax, boot_gdt_descr+2(%rip) + l...

On Tue, Apr 28, 2020 at 05:16:41PM +0200, Joerg Roedel wrote: > @@ -480,6 +500,22 @@ SYM_DATA_LOCAL(early_gdt_descr_base, .quad INIT_PER_CPU_VAR(gdt_page)) > SYM_DATA(phys_base, .quad 0x0) > EXPORT_SYMBOL(phys_base) > > +/* Boot GDT used when kernel addresses are not mapped yet */ > +SYM_DATA_LOCAL(boot_gdt_descr, .word boot_gdt_end - boot_gdt) >

On Tue, Apr 28, 2020 at 05:16:41PM +0200, Joerg Roedel wrote: > @@ -480,6 +500,22 @@ SYM_DATA_LOCAL(early_gdt_descr_base, .quad INIT_PER_CPU_VAR(gdt_page)) > SYM_DATA(phys_base, .quad 0x0) > EXPORT_SYMBOL(phys_base) > > +/* Boot GDT used when kernel addresses are not mapped yet */ > +SYM_DATA_LOCAL(boot_gdt_descr, .word boot_gdt_end - boot_gdt) >

Hi, here is the first public post of the patch-set to enable Linux to run under SEV-ES enabled hypervisors. The code is mostly feature-complete, but there are still a couple of bugs to fix. Nevertheless, given the size of the patch-set, I think it is about time to ask for initial feedback of the changes that come with it. To better understand the code here is a quick explanation of SEV-ES first.

Hi, here is the first public post of the patch-set to enable Linux to run under SEV-ES enabled hypervisors. The code is mostly feature-complete, but there are still a couple of bugs to fix. Nevertheless, given the size of the patch-set, I think it is about time to ask for initial feedback of the changes that come with it. To better understand the code here is a quick explanation of SEV-ES first.

Changes: - patch v2: - Adapt patch to work post KPTI and compiler changes - Redo all performance testing with latest configs and compilers - Simplify mov macro on PIE (MOVABS now) - Reduce GOT footprint - patch v1: - Simplify ftrace implementation. - Use gcc mstack-protector-guard-reg=%gs with PIE when possible. - rfc v3: - Use --emit-relocs instead of -pie to reduce

Changes: - patch v2: - Adapt patch to work post KPTI and compiler changes - Redo all performance testing with latest configs and compilers - Simplify mov macro on PIE (MOVABS now) - Reduce GOT footprint - patch v1: - Simplify ftrace implementation. - Use gcc mstack-protector-guard-reg=%gs with PIE when possible. - rfc v3: - Use --emit-relocs instead of -pie to reduce

These patches make the changes necessary to build the kernel as Position Independent Executable (PIE) on x86_64. A PIE kernel can be relocated below the top 2G of the virtual address space. It allows to optionally extend the KASLR randomization range from 1G to 3G. Thanks a lot to Ard Biesheuvel & Kees Cook on their feedback on compiler changes, PIE support and KASLR in general. Thanks to

These patches make the changes necessary to build the kernel as Position Independent Executable (PIE) on x86_64. A PIE kernel can be relocated below the top 2G of the virtual address space. It allows to optionally extend the KASLR randomization range from 1G to 3G. Thanks a lot to Ard Biesheuvel & Kees Cook on their feedback on compiler changes, PIE support and KASLR in general. Thanks to

Hi, here is the next version of changes to enable Linux to run as an SEV-ES guest. The code was rebased to v5.7-rc3 and got a fair number of changes since the last version. What is SEV-ES ============== SEV-ES is an acronym for 'Secure Encrypted Virtualization - Encrypted State' and means a hardware feature of AMD processors which hides the register state of VCPUs to the hypervisor by

Hi, here is the next version of changes to enable Linux to run as an SEV-ES guest. The code was rebased to v5.7-rc3 and got a fair number of changes since the last version. What is SEV-ES ============== SEV-ES is an acronym for 'Secure Encrypted Virtualization - Encrypted State' and means a hardware feature of AMD processors which hides the register state of VCPUs to the hypervisor by

Changes: - patch v3: - Update on message to describe longer term PIE goal. - Minor change on ftrace if condition. - Changed code using xchgq. - patch v2: - Adapt patch to work post KPTI and compiler changes - Redo all performance testing with latest configs and compilers - Simplify mov macro on PIE (MOVABS now) - Reduce GOT footprint - patch v1: - Simplify ftrace

Changes: - patch v1: - Simplify ftrace implementation. - Use gcc mstack-protector-guard-reg=%gs with PIE when possible. - rfc v3: - Use --emit-relocs instead of -pie to reduce dynamic relocation space on mapped memory. It also simplifies the relocation process. - Move the start the module section next to the kernel. Remove the need for -mcmodel=large on modules. Extends

Changes: - patch v1: - Simplify ftrace implementation. - Use gcc mstack-protector-guard-reg=%gs with PIE when possible. - rfc v3: - Use --emit-relocs instead of -pie to reduce dynamic relocation space on mapped memory. It also simplifies the relocation process. - Move the start the module section next to the kernel. Remove the need for -mcmodel=large on modules. Extends

From: Joerg Roedel <jroedel at suse.de> Hi, here is a rebased version of the latest SEV-ES patches. They are now based on latest tip/master instead of upstream Linux and include the necessary changes. Changes to v4 are in particular: - Moved early IDT setup code to idt.c, because the idt_descr and the idt_table are now static - This required to make stack protector work early (or