search for: insn_fetch_from_us

...> #VC handler uses the GHCB and the NMI handler causes another #VC, then > the contents of the GHCB needs to be backed up, so that it doesn't > destroy the GHCB contents of the first #VC handling path. Isn't it possible for the #VC handler to hit a #PF, e.g. on copy_from_user() in insn_fetch_from_user()? If that happens, what prevents the #PF handler from hitting a #VC? AIUI, do_vmm_communication() panics if the backup GHCB is already in use, e.g. #VC->#PF->#VC->NMI->#VC would be fatal.

.../arch/x86/include/asm/insn-eval.h index b8b9ef1bbd06..b4ff3e3316d1 100644 --- a/arch/x86/include/asm/insn-eval.h +++ b/arch/x86/include/asm/insn-eval.h @@ -21,5 +21,7 @@ unsigned long insn_get_seg_base(struct pt_regs *regs, int seg_reg_idx); int insn_get_code_seg_params(struct pt_regs *regs); int insn_fetch_from_user(struct pt_regs *regs, unsigned char buf[MAX_INSN_SIZE]); +bool insn_decode(struct pt_regs *regs, struct insn *insn, + unsigned char buf[MAX_INSN_SIZE], int buf_size); #endif /* _ASM_X86_INSN_EVAL_H */ diff --git a/arch/x86/kernel/umip.c b/arch/x86/kernel/umip.c index c9e5345da793..47d4d...

...s == -EFAULT)) { + ctxt->fi.vector = X86_TRAP_PF; + ctxt->fi.error_code = 0; + ctxt->fi.cr2 = ctxt->regs->ip; + return ES_EXCEPTION; + } + + insn_init(&ctxt->insn, buffer, MAX_INSN_SIZE - res, 1); + insn_get_length(&ctxt->insn); + } else { + res = insn_fetch_from_user(ctxt->regs, buffer); + if (res == 0) { + ctxt->fi.vector = X86_TRAP_PF; + ctxt->fi.cr2 = ctxt->regs->ip; + ctxt->fi.error_code = X86_PF_INSTR | X86_PF_USER; + return ES_EXCEPTION; + } + + if (!insn_decode(ctxt->regs, &ctxt->insn, buffer, res)) +...

On Tue, Apr 28, 2020 at 05:16:57PM +0200, Joerg Roedel wrote: > diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c > index a4fa7f351bf2..bc3a58427028 100644 > --- a/arch/x86/kernel/sev-es.c > +++ b/arch/x86/kernel/sev-es.c > @@ -10,6 +10,7 @@ > #include <linux/sched/debug.h> /* For show_regs() */ > #include <linux/percpu-defs.h> > #include

On Tue, Apr 28, 2020 at 05:16:57PM +0200, Joerg Roedel wrote: > diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c > index a4fa7f351bf2..bc3a58427028 100644 > --- a/arch/x86/kernel/sev-es.c > +++ b/arch/x86/kernel/sev-es.c > @@ -10,6 +10,7 @@ > #include <linux/sched/debug.h> /* For show_regs() */ > #include <linux/percpu-defs.h> > #include

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

From: Joerg Roedel <jroedel at suse.de> Hi, here is the fourth version of the SEV-ES Guest Support patches. I addressed the review comments sent to me for the previous version and rebased the code v5.8-rc5. The biggest change in this version is the IST handling code for the #VC handler. I adapted the entry code for the #VC handler to the big pile of entry code changes merged into

From: Joerg Roedel <jroedel at suse.de> Hi, here is the fourth version of the SEV-ES Guest Support patches. I addressed the review comments sent to me for the previous version and rebased the code v5.8-rc5. The biggest change in this version is the IST handling code for the #VC handler. I adapted the entry code for the #VC handler to the big pile of entry code changes merged into

From: Joerg Roedel <jroedel at suse.de> Hi, here is the new version of the SEV-ES client enabling patch-set. It is based on the latest tip/master branch and contains the necessary changes. In particular those ar: - Enabling CR4.FSGSBASE early on supported processors so that early #VC exceptions on APs can be handled. - Add another patch (patch 1) to fix a KVM frame-size build

From: Joerg Roedel <jroedel at suse.de> Hi, here is a new version of the SEV-ES Guest Support patches for x86. The previous versions can be found as a linked list starting here: https://lore.kernel.org/lkml/20200824085511.7553-1-joro at 8bytes.org/ I updated the patch-set based on ther review comments I got and the discussions around it. Another important change is that the early IDT

From: Joerg Roedel <jroedel at suse.de> Hi, here is a new version of the SEV-ES Guest Support patches for x86. The previous versions can be found as a linked list starting here: https://lore.kernel.org/lkml/20200824085511.7553-1-joro at 8bytes.org/ I updated the patch-set based on ther review comments I got and the discussions around it. Another important change is that the early IDT

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