diff mbox series

[RFC,V5,02/15] x86/hyperv: Decrypt hv vp assist page in sev-snp enlightened guest

Message ID 20230501085726.544209-3-ltykernel@gmail.com
State New
Headers
Series x86/hyperv/sev: Add AMD sev-snp enlightened guest support on hyperv |

Commit Message

Tianyu Lan May 1, 2023, 8:57 a.m. UTC 
  From: Tianyu Lan <tiala@microsoft.com>

hv vp assist page is shared between sev snp guest and hyperv. Decrypt
the page when use it.

Signed-off-by: Tianyu Lan <tiala@microsoft.com>
---
 arch/x86/hyperv/hv_init.c | 6 ++++++
 1 file changed, 6 insertions(+)

Comments

Tom Lendacky May 1, 2023, 3:10 p.m. UTC | #1 
On 5/1/23 03:57, Tianyu Lan wrote:
> From: Tianyu Lan <tiala@microsoft.com>
> 
> hv vp assist page is shared between sev snp guest and hyperv. Decrypt
> the page when use it.

You aren't actually decrypting the page, you're changing the mapping from 
private/encrypted to shared/unencrypted (hence the memset that follows to 
clear the page to zeroes).

And please capitalize where necessary, e.g., SEV-SNP, Hyper-V, etc.

Thanks,
Tom

> 
> Signed-off-by: Tianyu Lan <tiala@microsoft.com>
> ---
>   arch/x86/hyperv/hv_init.c | 6 ++++++
>   1 file changed, 6 insertions(+)
> 
> diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
> index a5f9474f08e1..9f3e2d71d015 100644
> --- a/arch/x86/hyperv/hv_init.c
> +++ b/arch/x86/hyperv/hv_init.c
> @@ -18,6 +18,7 @@
>   #include <asm/hyperv-tlfs.h>
>   #include <asm/mshyperv.h>
>   #include <asm/idtentry.h>
> +#include <asm/set_memory.h>
>   #include <linux/kexec.h>
>   #include <linux/version.h>
>   #include <linux/vmalloc.h>
> @@ -113,6 +114,11 @@ static int hv_cpu_init(unsigned int cpu)
>   
>   	}
>   	if (!WARN_ON(!(*hvp))) {
> +		if (hv_isolation_type_en_snp()) {
> +			WARN_ON_ONCE(set_memory_decrypted((unsigned long)(*hvp), 1));
> +			memset(*hvp, 0, PAGE_SIZE);
> +		}
> +
>   		msr.enable = 1;
>   		wrmsrl(HV_X64_MSR_VP_ASSIST_PAGE, msr.as_uint64);
>   	}
diff mbox series

Patch

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index a5f9474f08e1..9f3e2d71d015 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -18,6 +18,7 @@ 
 #include <asm/hyperv-tlfs.h>
 #include <asm/mshyperv.h>
 #include <asm/idtentry.h>
+#include <asm/set_memory.h>
 #include <linux/kexec.h>
 #include <linux/version.h>
 #include <linux/vmalloc.h>
@@ -113,6 +114,11 @@  static int hv_cpu_init(unsigned int cpu)
 
 	}
 	if (!WARN_ON(!(*hvp))) {
+		if (hv_isolation_type_en_snp()) {
+			WARN_ON_ONCE(set_memory_decrypted((unsigned long)(*hvp), 1));
+			memset(*hvp, 0, PAGE_SIZE);
+		}
+
 		msr.enable = 1;
 		wrmsrl(HV_X64_MSR_VP_ASSIST_PAGE, msr.as_uint64);
 	}