Re: [PATCH 62/70] x86/kvm: Add KVM specific VMMCALL handling under SEV-ES
From: David Rientjes <rientjes@google.com>
Date: 2020-03-20 21:24:05
Also in:
kvm, lkml
On Thu, 19 Mar 2020, Joerg Roedel wrote:
quoted hunk ↗ jump to hunk
From: Tom Lendacky <thomas.lendacky@amd.com> Implement the callbacks to copy the processor state required by KVM to the GHCB. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> [ jroedel@suse.de: - Split out of a larger patch - Adapt to different callback functions ] Co-developed-by: Joerg Roedel <redacted> Signed-off-by: Joerg Roedel <redacted> --- arch/x86/kernel/kvm.c | 35 +++++++++++++++++++++++++++++------ 1 file changed, 29 insertions(+), 6 deletions(-)diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 6efe0410fb72..0e3fc798d719 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c@@ -34,6 +34,8 @@ #include <asm/hypervisor.h> #include <asm/tlb.h> #include <asm/cpuidle_haltpoll.h> +#include <asm/ptrace.h> +#include <asm/svm.h> static int kvmapf = 1;@@ -729,13 +731,34 @@ static void __init kvm_init_platform(void) x86_platform.apic_post_init = kvm_apic_init; } +#if defined(CONFIG_AMD_MEM_ENCRYPT) +static void kvm_sev_es_hcall_prepare(struct ghcb *ghcb, struct pt_regs *regs) +{ + /* RAX and CPL are already in the GHCB */ + ghcb_set_rbx(ghcb, regs->bx); + ghcb_set_rcx(ghcb, regs->cx); + ghcb_set_rdx(ghcb, regs->dx); + ghcb_set_rsi(ghcb, regs->si);
Is it possible to check the hypercall from RAX and only copy the needed regs or is there a requirement that they must all be copied unconditionally?
+}
+
+static bool kvm_sev_es_hcall_finish(struct ghcb *ghcb, struct pt_regs *regs)
+{
+ /* No checking of the return state needed */
+ return true;
+}
+#endif
+
const __initconst struct hypervisor_x86 x86_hyper_kvm = {
- .name = "KVM",
- .detect = kvm_detect,
- .type = X86_HYPER_KVM,
- .init.guest_late_init = kvm_guest_init,
- .init.x2apic_available = kvm_para_available,
- .init.init_platform = kvm_init_platform,
+ .name = "KVM",
+ .detect = kvm_detect,
+ .type = X86_HYPER_KVM,
+ .init.guest_late_init = kvm_guest_init,
+ .init.x2apic_available = kvm_para_available,
+ .init.init_platform = kvm_init_platform,
+#if defined(CONFIG_AMD_MEM_ENCRYPT)
+ .runtime.sev_es_hcall_prepare = kvm_sev_es_hcall_prepare,
+ .runtime.sev_es_hcall_finish = kvm_sev_es_hcall_finish,
+#endif
};
static __init int activate_jump_labels(void)
--
2.17.1