Re: [PATCH v3 3/5] mm: x86: Invoke hypercall when page encryption status is changed

Hello Boris, Paolo,

On Thu, Jun 10, 2021 at 08:30:52PM +0200, Borislav Petkov wrote:

On Tue, Jun 08, 2021 at 06:06:26PM +0000, Ashish Kalra wrote:

quoted

+void notify_range_enc_status_changed(unsigned long vaddr, int npages,
+				    bool enc)

You don't need to break this line.

quoted

@@ -285,12 +333,13 @@ static void __init __set_clr_pte_enc(pte_t *kpte, int level, bool enc)
 static int __init early_set_memory_enc_dec(unsigned long vaddr,
 					   unsigned long size, bool enc)
 {
-	unsigned long vaddr_end, vaddr_next;
+	unsigned long vaddr_end, vaddr_next, start;
 	unsigned long psize, pmask;
 	int split_page_size_mask;
 	int level, ret;
 	pte_t *kpte;
 
+	start = vaddr;
 	vaddr_next = vaddr;
 	vaddr_end = vaddr + size;
 

@@ -345,6 +394,8 @@ static int __init early_set_memory_enc_dec(unsigned long vaddr,
 
 	ret = 0;
 
+	notify_range_enc_status_changed(start, PAGE_ALIGN(size) >> PAGE_SHIFT,
+					enc);

Ditto.

quoted

 out:
 	__flush_tlb_all();
 	return ret;

diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index 156cd235659f..9729cb0d99e3 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c

@@ -2020,6 +2020,13 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
 	 */
 	cpa_flush(&cpa, 0);
 
+	/*
+	 * Notify hypervisor that a given memory range is mapped encrypted
+	 * or decrypted. The hypervisor will use this information during the
+	 * VM migration.
+	 */

Simplify that comment:

        /*
         * Notify the hypervisor about the encryption status change of the memory
	 * range. It will use this information during the VM migration.
         */


With those nitpicks fixed:

Reviewed-by: Borislav Petkov <redacted>

Paulo, if you want me to take this, lemme know, but I think it'll
conflict with patch 5 so perhaps it all should go together through the
kvm tree...

Will these patches be merged into 5.14 ?

I have posted another version (v5) for patch 5 after more review comments
from Boris, so please pull in all these patches together. 

Thanks,
Ashish

Thx.

-- 
Regards/Gruss,
    Boris.

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